M&T Bank (MTB) 10-Q 5 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Trading Symbol	MTB
Entity Registrant Name	M&T BANK CORPORATION
Entity Central Index Key	0000036270
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		128,280,043
Entity File Number	1-9861
Entity Tax Identification Number	16-0968385
Entity Incorporation, State or Country Code	NY
Title of 12(b) Security	Common Stock, $.50 par value
Security Exchange Name	NYSE
Entity Address, Address Line One	One M & T Plaza
Entity Address, Postal Zip Code	14203
Entity Address, City or Town	Buffalo
Entity Address, State or Province	NY
City Area Code	716
Local Phone Number	635-4000
Document Quarterly Report	true
Document Transition Report	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets
Cash and due from banks	$ 1,354,815	$ 1,432,805
Interest-bearing deposits at banks	20,888,341	7,190,154
Federal funds sold		3,500
Trading account	1,293,534	470,129
Investment securities (includes pledged securities that can be sold or repledged of $198,375 at June 30, 2020; $200,339 at December 31, 2019)
Available for sale (cost: $5,583,688 at June 30, 2020; $6,258,276 at December 31, 2019)	5,821,274	6,318,776
Held to maturity (fair value: $2,266,087 at June 30, 2020; $2,699,206 at December 31, 2019)	2,158,982	2,656,917
Equity and other securities (cost: $453,384 at June 30, 2020; $487,041 at December 31, 2019)	474,088	521,558
Total investment securities	8,454,344	9,497,251
Loans and leases	98,197,650	91,188,525
Unearned discount	(440,102)	(265,656)
Loans and leases, net of unearned discount	97,757,548	90,922,869
Allowance for credit losses	(1,638,236)	(1,051,071)
Loans and leases, net	96,119,312	89,871,798
Premises and equipment	1,155,281	1,140,924
Goodwill	4,593,112	4,593,112
Core deposit and other intangible assets	21,208	29,034
Accrued interest and other assets	5,657,022	5,644,050
Total assets	139,536,969	119,872,757
Liabilities
Noninterest-bearing deposits	45,397,843	32,396,407
Savings and interest-checking deposits	63,623,406	54,932,162
Time deposits	5,078,426	5,757,456
Deposits at Cayman Islands office	868,284	1,684,044
Total deposits	114,967,959	94,770,069
Short-term borrowings	52,298	62,363
Accrued interest and other liabilities	2,250,316	2,337,490
Long-term borrowings	6,321,291	6,986,186
Total liabilities	123,591,864	104,156,108
Shareholders' equity
Preferred stock, $1.00 par, 1,000,000 shares authorized; Issued and outstanding: Liquidation preference of $1,000 per share: 350,000 shares at June 30, 2020 and December 31, 2019; Liquidation preference of $10,000 per share: 90,000 shares at June 30, 2020 and December 31, 2019	1,250,000	1,250,000
Common stock, $.50 par, 250,000,000 shares authorized, 159,741,898 shares issued at June 30, 2020 and December 31, 2019	79,871	79,871
Common stock issuable, 17,786 shares at June 30, 2020; 21,534 shares at December 31, 2019	1,308	1,566
Additional paid-in capital	6,599,069	6,593,539
Retained earnings	12,919,345	12,820,916
Accumulated other comprehensive income (loss), net	244,630	(206,680)
Treasury stock — common, at cost — 31,465,769 shares at June 30, 2020; 29,174,402 shares at December 31, 2019	(5,149,118)	(4,822,563)
Total shareholders’ equity	15,945,105	15,716,649
Total liabilities and shareholders’ equity	$ 139,536,969	$ 119,872,757

Consolidated Balance Sheet (U_2

Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Pledged securities that can be sold or repledged	$ 198,375	$ 200,339
Investment securities, available for sale, amortized cost	5,583,688	6,258,276
Investment securities, held to maturity, fair value	2,266,087	2,699,206
Equity and other securities, cost	$ 453,384	$ 487,041
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	1,000,000	1,000,000
Common stock, par value	$ 0.50	$ 0.50
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	159,741,898	159,741,898
Common stock issuable, shares	17,786	21,534
Treasury stock, common shares	31,465,769	29,174,402
Series A Series C Series And E Preferred Stock [Member]
Preferred stock, shares issued	350,000	350,000
Preferred stock, shares outstanding	350,000	350,000
Preferred stock, liquidation preference per share	$ 1,000	$ 1,000
Series F And Series G Preferred Stock [Member]
Preferred stock, shares issued	90,000	90,000
Preferred stock, shares outstanding	90,000	90,000
Preferred stock, liquidation preference per share	$ 10,000	$ 10,000

Consolidated Statement of Incom

Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest income
Loans and leases, including fees	$ 980,372	$ 1,125,577	$ 2,027,193	$ 2,243,490
Investment securities
Fully taxable	47,219	75,578	97,329	155,989
Exempt from federal taxes	29	77	104	172
Deposits at banks	4,179	36,325	23,145	63,732
Other	443	356	4,890	839
Total interest income	1,032,242	1,237,913	2,152,661	2,464,222
Interest expense
Savings and interest-checking deposits	26,454	91,557	104,456	167,695
Time deposits	19,883	24,931	41,755	46,012
Deposits at Cayman Islands office	161	6,039	3,580	10,777
Short-term borrowings	2	7,893	25	14,606
Long-term borrowings	28,605	66,012	68,903	133,591
Total interest expense	75,105	196,432	218,719	372,681
Net interest income	957,137	1,041,481	1,933,942	2,091,541
Provision for credit losses	325,000	55,000	575,000	77,000
Net interest income after provision for credit losses	632,137	986,481	1,358,942	2,014,541
Other income
Brokerage services income	10,463	12,478	23,592	24,954
Trading account and foreign exchange gains	8,290	18,453	29,306	29,255
Gain (loss) on bank investment securities	6,969	8,911	(13,813)	20,752
Other revenues from operations	87,190	112,763	220,366	247,200
Total other income	487,273	512,095	1,016,633	1,012,860
Other expense
Salaries and employee benefits	458,842	455,737	995,685	954,937
Equipment and net occupancy	77,089	79,150	156,729	158,497
Outside data processing and software	61,376	55,234	125,786	107,651
FDIC assessments	14,207	9,772	26,478	19,198
Advertising and marketing	9,842	24,046	32,217	44,321
Printing, postage and supplies	11,260	10,324	22,112	20,179
Amortization of core deposit and other intangible assets	3,913	5,077	7,826	10,097
Other costs of operations	170,513	233,692	346,625	452,500
Total other expense	807,042	873,032	1,713,458	1,767,380
Income before taxes	312,368	625,544	662,117	1,260,021
Income taxes	71,314	152,284	152,241	304,019
Net income	241,054	473,260	509,876	956,002
Net income available to common shareholders
Basic	223,098	452,632	473,794	914,718
Diluted	$ 223,099	$ 452,633	$ 473,795	$ 914,719
Net income per common share
Basic	$ 1.74	$ 3.34	$ 3.67	$ 6.69
Diluted	$ 1.74	$ 3.34	$ 3.67	$ 6.69
Average common shares outstanding
Basic	128,275	135,433	128,986	136,654
Diluted	128,333	135,464	129,044	136,685
Mortgage Banking Revenues [Member]
Other income
Revenue from contract with customer	$ 145,024	$ 107,321	$ 272,933	$ 202,632
Service Charges on Deposit Accounts [Member]
Other income
Revenue from contract with customer	77,455	107,787	183,616	210,899
Trust Income [Member]
Other income
Revenue from contract with customer	$ 151,882	$ 144,382	$ 300,633	$ 277,168

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Partners Capital [Abstract]
Net income	$ 241,054	$ 473,260	$ 509,876	$ 956,002
Other comprehensive income, net of tax and reclassification adjustments:
Net unrealized gains on investment securities	34,951	69,853	132,399	154,444
Cash flow hedges adjustments	(8,959)	102,050	303,761	146,971
Foreign currency translation adjustments	(51)	(675)	(2,994)	(400)
Defined benefit plans liability adjustments	8,856	3,823	18,144	6,108
Total other comprehensive income	34,797	175,051	451,310	307,123
Total comprehensive income	$ 275,851	$ 648,311	$ 961,186	$ 1,263,125

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities
Net income	$ 509,876	$ 956,002
Adjustments to reconcile net income to net cash provided by operating activities
Provision for credit losses	575,000	77,000
Depreciation and amortization of premises and equipment	108,748	101,983
Amortization of capitalized servicing rights	37,971	34,017
Amortization of core deposit and other intangible assets	7,826	10,097
Provision for deferred income taxes	(90,093)	15,817
Asset write-downs	15,626	52,324
Net gain on sales of assets	(5,808)	(10,521)
Net change in accrued interest receivable, payable	(48,790)	5,650
Net change in other accrued income and expense	6,403	(144,714)
Net change in loans originated for sale	(220,368)	(218,925)
Net change in trading account assets and liabilities	(765,314)	(398,552)
Net cash provided by operating activities	131,077	480,178
Cash flows from investing activities
Proceeds from sales of investment securities equity and other	54,232	580,489
Proceeds from maturities of investment securities Available for sale	662,253	1,506,273
Proceeds from maturities of investment securities Held to maturity	502,093	213,086
Purchases of investment securities Available for sale	(4,052)	(2,694)
Purchases of investment securities Held to maturity	(8,995)	(495,277)
Purchases of investment securities equity and other	(20,575)	(461,749)
Net increase in loans and leases	(6,713,727)	(1,259,545)
Net increase in interest-bearing deposits at banks	(13,698,187)	(686,556)
Capital expenditures, net	(93,651)	(82,657)
Net decrease in loan servicing advances	178,984	23,663
Other, net	197,377	84,108
Net cash used by investing activities	(18,944,248)	(580,859)
Cash flows from financing activities
Net increase in deposits	20,199,033	1,525,777
Net increase (decrease) in short-term borrowings	(10,065)	213,012
Payments on long-term borrowings	(754,425)	(876,581)
Purchases of treasury stock	(373,750)	(767,612)
Dividends paid — common	(284,690)	(274,037)
Dividends paid — preferred	(34,156)	(36,260)
Other, net	(10,266)	(17,446)
Net cash provided (used) by financing activities	18,731,681	(233,147)
Net decrease in cash, cash equivalents and restricted cash	(81,490)	(333,828)
Cash, cash equivalents and restricted cash at beginning of period	1,436,305	1,605,439
Cash, cash equivalents and restricted cash at end of period	1,354,815	1,271,611
Supplemental disclosure of cash flow information
Interest received during the period	2,156,881	2,444,623
Interest paid during the period	223,874	361,179
Income taxes paid during the period	61,759	243,404
Supplemental schedule of noncash investing and financing activities
Real estate acquired in settlement of loans	17,885	39,456
Securitization of residential mortgage loans allocated to Available-for-sale investment securities		5,379
Securitization of residential mortgage loans allocated to capitalized servicing rights		83
Adoption of lease accounting standard - Right-of-use assets		393,877
Adoption of lease accounting standard - Other liabilities		398,810
Additions to right-of-use assets under operating leases	$ 30,585	$ 44,928

Consolidated Statement of Chang

Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands		Total	ASU 2016-13 [Member]	Preferred Stock [Member]	Common Stock [Member]	Common Stock Issuable [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]ASU 2016-13 [Member]	Accumulated Other Comprehensive Income (Loss), Net [Member]	Treasury Stock [Member]
Beginning balance at Dec. 31, 2018		$ 15,460,191		$ 1,231,500	$ 79,883	$ 1,726	$ 6,579,342	$ 11,516,672		$ (420,081)	$ (3,528,851)
Total comprehensive income		1,263,125						956,002		307,123
Preferred stock cash dividends	[1]	(36,260)						(36,260)
Purchases of treasury stock		(767,612)									(767,612)
Stock-based compensation transactions, net		46,418			(12)	(200)	(1,739)	(101)			48,470
Common stock cash dividends		(274,035)						(274,035)
Ending balance at Jun. 30, 2019		15,691,827		1,231,500	79,871	1,526	6,577,603	12,162,278		(112,958)	(4,247,993)
Beginning balance at Mar. 31, 2019		15,587,529		1,231,500	79,871	1,514	6,568,480	11,842,371		(288,009)	(3,848,198)
Total comprehensive income		648,311						473,260		175,051
Preferred stock cash dividends	[1]	(18,130)						(18,130)
Purchases of treasury stock		(401,984)									(401,984)
Stock-based compensation transactions, net		11,274				12	9,123	(50)			2,189
Common stock cash dividends		(135,173)						(135,173)
Ending balance at Jun. 30, 2019		15,691,827		1,231,500	79,871	1,526	6,577,603	12,162,278		(112,958)	(4,247,993)
Beginning balance at Dec. 31, 2019		15,716,649		1,250,000	79,871	1,566	6,593,539	12,820,916		(206,680)	(4,822,563)
Adoption of new accounting standard for credit losses			$ (91,925)						$ (91,925)
Total comprehensive income		961,186						509,876		451,310
Preferred stock cash dividends	[1]	(34,128)						(34,128)
Purchases of treasury stock		(373,750)									(373,750)
Stock-based compensation transactions, net		52,261				(258)	5,530	(206)			47,195
Common stock cash dividends		(285,188)						(285,188)
Ending balance at Jun. 30, 2020		15,945,105		1,250,000	79,871	1,308	6,599,069	12,919,345		244,630	(5,149,118)
Beginning balance at Mar. 31, 2020		15,815,794		1,250,000	79,871	1,292	6,588,407	12,837,390		209,833	(5,150,999)
Total comprehensive income		275,851						241,054		34,797
Preferred stock cash dividends	[1]	(17,050)						(17,050)
Stock-based compensation transactions, net		12,455				16	10,662	(104)			1,881
Common stock cash dividends		(141,945)						(141,945)
Ending balance at Jun. 30, 2020		$ 15,945,105		$ 1,250,000	$ 79,871	$ 1,308	$ 6,599,069	$ 12,919,345		$ 244,630	$ (5,149,118)
[1]	For the three-month and six-month periods ended June 30, 2020, dividends per preferred share were: Preferred Series E - $16.125 and $32.25, respectively; Preferred Series F - $128.125 and $256.25, respectively; and Preferred Series G - $125.00 and $250.694, respectively. Dividends per preferred share for the three-month and six-month periods ended June 30, 2019 were: Preferred Series A - $15.9375 and $31.875, respectively; Preferred Series C - $15.9375 and $31.875, respectively; Preferred Series E - $16.125 and $32.25, respectively; and Preferred Series F - $128.125 and $256.25, respectively.

Consolidated Statement of Cha_2

Consolidated Statement of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Retained Earnings [Member]
Common stock per share dividend amount	$ 1.10	$ 1	$ 2.20	$ 2
Preferred Series A [Member]
Preferred stock per share dividend amount		15.9375		31.875
Preferred Series C [Member]
Preferred stock per share dividend amount		15.9375		31.875
Preferred Series E [Member]
Preferred stock per share dividend amount	16.125	16.125	32.25	32.25
Preferred Series F [Member]
Preferred stock per share dividend amount	128.125	$ 128.125	256.25	$ 256.25
Preferred Series G [Member]
Preferred stock per share dividend amount	$ 125		$ 250.694

Significant accounting policies

Significant accounting policies and current environment	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Significant accounting policies and current environment	1. Significant accounting policies and current environment The consolidated interim financial statements of M&T Bank Corporation (“M&T”) and subsidiaries (“the Company”) were compiled in accordance with generally accepted accounting principles (“GAAP”) using the accounting policies set forth in note 1 of Notes to Financial Statements included in Form 10-K for the year ended December 31, 2019 (“2019 Annual Report”), except that effective January 1, 2020 the Company adopted accounting guidance related to the recognition of expected credit losses that is discussed in notes 2, 3 and 15 herein. The financial statements contain all adjustments which are, in the opinion of management, necessary for a fair statement of the Company’s financial position, results of operations and cash flows for the interim periods presented. The United States has been operating under a state of emergency related to the Coronavirus Disease 2019 (“COVID-19”) pandemic since March 13, 2020. The direct and indirect effects of the COVID-19 pandemic have resulted in a dramatic reduction in economic activity that has severely hampered the ability for businesses and consumers to meet their current repayment obligations. The effects of the pandemic contributed to a significant increase in the provision for credit losses during the first two quarters of 2020. The Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”), in addition to providing financial assistance to both businesses and consumers, creates a forbearance program for federally-backed mortgage loans, protects borrowers from negative credit reporting due to loan accommodations related to the national emergency, and provides financial institutions the option to temporarily suspend certain requirements under GAAP related to troubled debt restructurings for a limited period of time to account for the effects of COVID-19. The bank regulatory agencies have likewise issued guidance encouraging financial institutions to work prudently with borrowers who are, or may be, unable to meet their contractual payment obligations because of the effects of COVID-19. That guidance, with concurrence of the Financial Accounting Standards Board, and provisions of the CARES Act allow modifications made on a good faith basis in response to COVID-19 to borrowers who were generally current with their payments prior to any relief, to not be treated as troubled debt restructurings nor be reported as past due. Modifications may include payment deferrals, fee waivers, extensions of repayment term, or other delays in payment. The Company has been working with its customers affected by COVID-19 and has granted modifications across many of its loan portfolios. To the extent that such modifications meet the criteria previously described, the modified loans have not been classified as troubled debt restructurings nor reported as past due.

Investment securities

Investment securities	6 Months Ended
	Jun. 30, 2020
Investments Debt And Equity Securities [Abstract]
Investment securities	2. Investment securities The amortized cost and estimated fair value of investment securities were as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (In thousands) June 30, 2020 Investment securities available for sale: U.S. Treasury and federal agencies $ 9,653 $ 246 $ 6 $ 9,893 Obligations of states and political subdivisions 513 1 3 511 Mortgage-backed securities: Government issued or guaranteed 5,439,071 252,007 917 5,690,161 Privately issued 16 — — 16 Other debt securities 134,435 914 14,656 120,693 5,583,688 253,168 15,582 5,821,274 Investment securities held to maturity: U.S. Treasury and federal agencies 2,999 — — 2,999 Obligations of states and political subdivisions 2,220 13 — 2,233 Mortgage-backed securities: Government issued or guaranteed 2,064,946 117,092 41 2,181,997 Privately issued 85,780 9,410 19,369 75,821 Other debt securities 3,037 — — 3,037 2,158,982 126,515 19,410 2,266,087 Total debt securities $ 7,742,670 $ 379,683 $ 34,992 $ 8,087,361 Equity and other securities: Readily marketable equity — at fair value $ 72,907 $ 20,704 $ — $ 93,611 Other — at cost 380,477 — — 380,477 Total equity and other securities $ 453,384 $ 20,704 $ — $ 474,088 December 31, 2019 Investment securities available for sale: U.S. Treasury and federal agencies $ 9,742 $ 41 $ 16 $ 9,767 Obligations of states and political subdivisions 776 2 3 775 Mortgage-backed securities: Government issued or guaranteed 6,113,913 88,634 21,607 6,180,940 Privately issued 16 — — 16 Other debt securities 133,829 2,046 8,597 127,278 6,258,276 90,723 30,223 6,318,776 Investment securities held to maturity: U.S. Treasury and federal agencies 249,862 286 — 250,148 Obligations of states and political subdivisions 4,140 16 — 4,156 Mortgage-backed securities: Government issued or guaranteed 2,306,180 50,381 1,992 2,354,569 Privately issued 93,496 11,779 18,181 87,094 Other debt securities 3,239 — — 3,239 2,656,917 62,462 20,173 2,699,206 Total debt securities $ 8,915,193 $ 153,185 $ 50,396 $ 9,017,982 Equity and other securities: Readily marketable equity — at fair value $ 105,524 $ 34,786 $ 269 $ 140,041 Other — at cost 381,517 — — 381,517 Total equity and other securities $ 487,041 $ 34,786 $ 269 $ 521,558 2. Investment securities, continued There were no significant gross realized gains or losses from sales of investment securities for the three-month and six-month periods ended June 30, 2020 and 2019. Unrealized gains on equity securities during the three months ended June 30, 2020 were $7 million and unrealized losses during the six months ended June 30, 2020 were $14 million, compared with unrealized gains of $9 million and $21 million during the three months and six months ended June 30, 2019, respectively. At June 30, 2020, the amortized cost and estimated fair value of debt securities by contractual maturity were as follows: Amortized Cost Estimated Fair Value (In thousands) Debt securities available for sale: Due in one year or less $ 6,067 6,089 Due after one year through five years 10,149 10,646 Due after five years through ten years 98,385 90,175 Due after ten years 30,000 24,187 144,601 131,097 Mortgage-backed securities available for sale 5,439,087 5,690,177 $ 5,583,688 5,821,274 Debt securities held to maturity: Due in one year or less $ 4,674 4,678 Due after one year through five years 545 554 Due after ten years 3,037 3,037 8,256 8,269 Mortgage-backed securities held to maturity 2,150,726 2,257,818 $ 2,158,982 2,266,087 2. Investment securities, continued A summary of investment securities that as of June 30, 2020 and December 31, 2019 had been in a continuous unrealized loss position for less than twelve months and those that had been in a continuous unrealized loss position for twelve months or longer follows: Less Than 12 Months 12 Months or More Fair Value Unrealized Losses Fair Value Unrealized Losses (In thousands) June 30, 2020 Investment securities available for sale: U.S. Treasury and federal agencies $ 985 (6 ) — — Obligations of states and political subdivisions — — 135 (3 ) Mortgage-backed securities: Government issued or guaranteed 23,855 (416 ) 25,930 (501 ) Other debt securities 54,951 (4,385 ) 54,318 (10,271 ) 79,791 (4,807 ) 80,383 (10,775 ) Investment securities held to maturity: Mortgage-backed securities: Government issued or guaranteed 8,430 (41 ) — — Privately issued 7,916 (22 ) 45,908 (19,347 ) 16,346 (63 ) 45,908 (19,347 ) Total $ 96,137 (4,870 ) 126,291 (30,122 ) December 31, 2019 Investment securities available for sale: U.S. Treasury and federal agencies $ 1,406 (7 ) 2,893 (9 ) Obligations of states and political subdivisions — — 277 (3 ) Mortgage-backed securities: Government issued or guaranteed 117,299 (222 ) 2,002,364 (21,385 ) Other debt securities 6,600 (354 ) 56,313 (8,243 ) 125,305 (583 ) 2,061,847 (29,640 ) Investment securities held to maturity: Mortgage-backed securities: Government issued or guaranteed 2,727 (5 ) 145,235 (1,987 ) Privately issued — — 49,656 (18,181 ) 2,727 (5 ) 194,891 (20,168 ) Total $ 128,032 (588 ) 2,256,738 (49,808 ) The Company owned 341 individual debt securities with aggregate gross unrealized losses of $35 million at June 30, 2020. Based on a review of each of the securities in the investment securities portfolio at June 30, 2020, the Company concluded that it expected to recover the amortized cost basis of its investment. As of June 30, 2020, the Company does not intend to sell nor is it anticipated that it would be required to sell any of its impaired investment securities at a loss. At June 30, 2020, the Company has not identified events or changes in circumstances which may have a significant adverse effect on the fair value of the $380 million of cost method equity securities. 2. Investment securities, continued As described in notes 3 and 15, on January 1, 2020 the Company adopted amended accounting guidance that requires an allowance for credit losses be deducted from the amortized cost basis of financial assets, including investment securities held to maturity, to present the net carrying value at the amount that is expected to be collected over their contractual term. The Company estimated no material allowance for credit losses for its investment securities classified as held-to-maturity at January 1, 2020 or June 30, 2020, as the substantial majority of such investment securities are obligations backed by the U.S. government or its agencies.

Loans and leases and the allowa

Loans and leases and the allowance for credit losses	6 Months Ended
	Jun. 30, 2020
Receivables [Abstract]
Loans and leases and the allowance for credit losses	3. Loans and leases and the allowance for credit losses Effective January 1, 2020 the Company adopted amended accounting guidance which requires an allowance for credit losses be deducted from the amortized cost basis of financial assets to present the net carrying value at the amount that is expected to be collected over their contractual term considering relevant information about past events, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount. The amended guidance also requires recording an allowance for credit losses for purchased financial assets with a more-than-insignificant amount of credit deterioration since origination. The initial allowance for these assets will be added to the purchase price at acquisition rather than being reported as an expense. Subsequent changes in the allowance will be recorded in the income statement as an adjustment to the provision for credit losses. The new guidance replaced the previous incurred loss model for determining the allowance for credit losses. The adoption resulted in a $132 million increase in the allowance for credit losses at January 1, 2020. Prior to January 1, 2020, the Company generally recognized the excess of cash flows expected at acquisition over the estimated fair value of the acquired loans as interest income over the remaining lives of such loans regardless of the borrowers’ repayment status. Effective with the adoption of the new accounting standard, the Company’s nonaccrual loan policy now applies to loans acquired at a discount. That change added $171 million to nonaccrual loans as of the January 1, 2020 adoption date. Past due and nonaccrual loans A summary of current, past due and nonaccrual loans as of June 30, 2020 and December 31, 2019 follows: Current 30-89 Days Past Due Accruing Loans Due 90 Days or More Nonaccrual Total (In thousands) June 30, 2020 Commercial, financial, leasing, etc. $ 28,855,500 53,005 10,703 284,654 $ 29,203,862 Real estate: Commercial 27,250,342 148,129 17,305 172,488 27,588,264 Residential builder and developer 1,418,354 33,752 — 1,748 1,453,854 Other commercial construction 7,983,195 23,911 24,801 85,426 8,117,333 Residential 12,746,530 218,870 479,027 306,907 13,751,334 Residential — limited documentation 1,715,896 25,537 — 118,695 1,860,128 Consumer: Home equity lines and loans 4,107,387 34,341 — 77,094 4,218,822 Recreational finance 6,342,914 30,170 — 24,152 6,397,236 Automobile 3,680,749 41,375 — 42,736 3,764,860 Other 1,346,276 8,910 3,919 42,750 1,401,855 Total $ 95,447,143 618,000 535,755 1,156,650 $ 97,757,548 3. Loans and leases and the allowance for credit losses, continued Current 30-89 Days Past Due Accruing Loans Due 90 Days or More (a) Accruing Loans Acquired a Discount Past Due 90 days or More (b) Purchased Impaired (c) Nonaccrual Total (In thousands) December 31, 2019 Commercial, financial, leasing, etc. $ 23,290,797 184,011 16,776 27 — 346,557 $ 23,838,168 Real estate: Commercial 26,311,414 165,579 6,740 — 15,601 158,474 26,657,808 Residential builder and developer 1,521,315 21,195 — — 753 3,982 1,547,245 Other commercial construction 7,204,148 95,346 3,360 — 1,237 32,770 7,336,861 Residential 12,760,040 451,274 486,515 5,788 143,145 235,663 14,082,425 Residential — limited documentation 1,858,037 65,215 181 — 66,809 83,427 2,073,669 Consumer: Home equity lines and loans 4,386,511 30,229 — 1,662 — 63,215 4,481,617 Recreational finance 5,484,997 36,827 — 99 — 14,219 5,536,142 Automobile 3,787,221 78,478 — — — 21,293 3,886,992 Other 1,395,240 45,978 5,156 32,056 — 3,512 1,481,942 Total $ 87,999,720 1,174,132 518,728 39,632 227,545 963,112 $ 90,922,869 (a) Excludes loans acquired at a discount. (b) Loans acquired at a discount that were recorded at fair value at acquisition date. This category does not include purchased impaired loans that are presented separately. (c) Accruing loans acquired at a discount that were impaired at acquisition date and recorded at fair value. A summary of outstanding loan balances for which COVID-19 related modifications were granted as of June 30, 2020 is presented below. These loans meet the criteria described in note 1 and, as such, are not considered past due or otherwise in default of loan terms. Loans to motor vehicle and recreational finance dealers comprised $3.3 billion and $823 million of the total COVID-19 modifications of commercial, financial, leasing and commercial real estate loans, respectively. (In thousands) Commercial, financial, leasing, etc. $ 5,302,196 Real estate: Commercial 7,802,006 Residential builder and developer 18,253 Other commercial construction 861,536 Residential 1,737,483 Residential — limited documentation 538,671 Consumer: Home equity lines and loans 88,162 Recreational finance 254,205 Automobile 326,113 Other 16,611 Total $ 16,945,236 3. Loans and leases and the allowance for credit losses, continued One-to-four family residential mortgage loans held for sale were $440 million and $414 million at June 30, 2020 and December 31, 2019, respectively. Commercial real estate loans held for sale were $255 million at June 30, 2020 and $28 million at December 31, 2019. The outstanding principal balance and the carrying amount of loans acquired at a discount that were recorded at fair value at the acquisition date for which interest income was recognized based on expected future cash flows that were included in the consolidated balance sheet at December 31, 2019 were as follows: (In thousands) Outstanding principal balance $ 769,414 Carrying amount: Commercial, financial, leasing, etc. 21,114 Commercial real estate 94,890 Residential real estate 341,807 Consumer 77,785 $ 535,596 Purchased impaired loans included in the table above totaled Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Purchased Other Purchased Other Impaired Acquired Impaired Acquired (In thousands) Balance at beginning of period $ 140,317 $ 93,687 $ 147,210 $ 96,907 Interest income (9,632 ) (9,666 ) (27,714 ) (19,383 ) Reclassifications from nonaccretable balance 16,419 3,457 27,608 8,322 Other (a) — 3,433 — 5,065 Balance at end of period $ 147,104 $ 90,911 $ 147,104 $ 90,911 (a) Other changes in expected cash flows included changes in interest rates and prepayment assumptions. Credit quality indicators The Company utilizes a loan grading system to differentiate risk amongst its commercial loans and commercial real estate loans. Loans with a lower expectation of default are assigned one of ten possible “pass” loan grades and are generally ascribed lower loss factors when determining the allowance for credit losses. Loans with an elevated level of credit risk are classified as “criticized” and are ascribed a higher loss factor when determining the allowance for credit losses. Criticized loans may be classified as “nonaccrual” if the Company no longer expects to collect all amounts according to the contractual terms of the loan agreement or the loan is delinquent 90 days or more. Loan officers in different geographic locations with the support of the Company’s credit department personnel continuously review and reassign loan grades based on their detailed knowledge of individual borrowers and their judgment of the impact on such borrowers resulting from changing conditions in their respective regions. Factors considered in assigning loan grades include borrower-specific information related to expected future cash flows and operating results, collateral values, geographic location, financial condition and performance, payment status, and other information. At least annually, updated financial information is obtained from commercial borrowers associated 3. Loans and leases and the allowance for credit losses, continued with pass grade loans and additional analysis is performed. On a quarterly basis, the Company’s centralized credit department reviews all criticized commercial loans and commercial real estate loans greater than $1 million to determine the appropriateness of the assigned loan grade, including whether the loan should be reported as accruing or nonaccruing. The following table summarizes the loan grades applied at June 30, 2020 to the various classes of the Compan Term Loans by Origination Year Revolving Revolving Loans Converted to Term 2020 2019 2018 2017 2016 Prior Loans Loans Total (In thousands) Commercial, financial, leasing, etc.: Loan grades: Pass $ 7,944,081 2,571,703 1,744,756 1,074,677 878,129 1,579,718 11,451,339 32,192 $ 27,276,595 Criticized accrual 313,697 88,164 164,361 64,980 50,254 82,987 868,964 9,206 1,642,613 Criticized nonaccrual 2,689 7,816 50,512 24,345 20,238 48,234 123,671 7,149 284,654 Total commercial, financial, leasing, etc. $ 8,260,467 2,667,683 1,959,629 1,164,002 948,621 1,710,939 12,443,974 48,547 $ 29,203,862 Real estate: Commercial: Loan grades: Pass $ 2,055,007 4,937,718 3,679,741 3,005,081 3,131,570 6,729,170 844,868 — $ 24,383,155 Criticized accrual 206,417 446,695 396,270 141,128 634,733 1,165,443 41,935 — 3,032,621 Criticized nonaccrual — 3,527 6,089 21,882 29,149 111,409 432 — 172,488 Total commercial real estate $ 2,261,424 5,387,940 4,082,100 3,168,091 3,795,452 8,006,022 887,235 — $ 27,588,264 Residential builder and developer: Loan grades: Pass $ 285,891 526,779 254,416 51,814 14,710 16,755 223,428 — $ 1,373,793 Criticized accrual 4,086 12,964 16,349 17,164 302 22,557 4,891 — 78,313 Criticized nonaccrual — — — — 302 1,446 — — 1,748 Total residential builder and developer $ 289,977 539,743 270,765 68,978 15,314 40,758 228,319 — $ 1,453,854 Other commercial construction: Loan grades: Pass $ 459,366 2,340,490 2,314,047 1,254,678 404,993 318,387 80,428 — $ 7,172,389 Criticized accrual 22,850 205,065 264,298 216,998 138,268 12,039 — — 859,518 Criticized nonaccrual — — — 350 57,773 22,171 5,132 — 85,426 Total other commercial construction $ 482,216 2,545,555 2,578,345 1,472,026 601,034 352,597 85,560 — $ 8,117,333 Increases to criticized loans as of June 30, 2020 as compared with March 31, 2020 were predominantly attributable to effects of the COVID-19 pandemic and the related regrading of loans totaled $3.7 billion, including $759 million of commercial loans, $2.3 billion of commercial real estate loans and $668 million of other commercial construction loans. 3. Loans and leases and the allowance for credit losses, continued The Company considers repayment performance a significant indicator of credit quality for its residential real estate loan and consumer loan portfolios. A summary of loans in accrual and nonaccrual status at June 30, 2020 for the various classes of the Company’s residential real estate loans and consumer loans by origination year is as follows. Term Loans by Origination Year Revolving Revolving Loans Converted to Term 2020 2019 2018 2017 2016 Prior Loans Loans Total (In thousands) Residential: Current $ 1,386,049 1,446,544 627,380 711,769 735,767 7,785,981 53,040 — $ 12,746,530 30-89 days past due 2,291 7,259 6,718 20,267 4,256 177,700 379 — 218,870 Accruing loans past due 90 days or more 117 8,995 26,337 118,899 25,353 299,326 — — 479,027 Nonaccrual 29 4,223 2,930 5,696 950 292,859 220 — 306,907 Total residential $ 1,388,486 1,467,021 663,365 856,631 766,326 8,555,866 53,639 — $ 13,751,334 Residential - limited documentation: Current $ — — — — — 1,715,896 — — $ 1,715,896 30-89 days past due — — — — — 25,537 — — 25,537 Accruing loans past due 90 days or more — — — — — — — — — Nonaccrual — — — — — 118,695 — — 118,695 Total residential - limited documentation $ — — — — — 1,860,128 — — $ 1,860,128 Consumer: Home equity lines and loans: Current $ 852 4,931 2,550 2,731 155 60,569 2,687,506 1,348,093 $ 4,107,387 30-89 days past due — 20 — — — 1,770 — 32,551 34,341 Accruing loans past due 90 days or more — — — — — — — — — Nonaccrual — — — — — 5,895 1,196 70,003 77,094 Total home equity lines and loans $ 852 4,951 2,550 2,731 155 68,234 2,688,702 1,450,647 $ 4,218,822 3. Loans and leases and the allowance for credit losses, continued Term Loans by Origination Year Revolving Revolving Loans Converted to Term 2020 2019 2018 2017 2016 Prior Loans Loans Total (In thousands) Recreational finance: Current $ 1,453,572 2,021,651 1,055,732 728,343 410,077 673,539 — — $ 6,342,914 30-89 days past due 2,415 7,557 5,208 5,096 2,815 7,079 — — 30,170 Accruing loans past due 90 days or more — — — — — — — — — Nonaccrual 783 3,479 4,229 4,844 2,666 8,151 — — 24,152 Total recreational finance $ 1,456,770 2,032,687 1,065,169 738,283 415,558 688,769 — — $ 6,397,236 Automobile: Current $ 567,784 1,341,719 802,096 595,776 253,239 120,135 — — $ 3,680,749 30-89 days past due 1,495 9,879 10,557 10,642 5,590 3,212 — — 41,375 Accruing loans past due 90 days or more — — — — — — — — — Nonaccrual 1,125 7,176 10,987 11,054 7,058 5,336 — — 42,736 Total automobile $ 570,404 1,358,774 823,640 617,472 265,887 128,683 — — $ 3,764,860 Other: Current $ 93,225 174,085 73,089 47,297 8,532 32,837 915,187 2,024 $ 1,346,276 30-89 days past due 1,246 778 557 311 56 389 5,016 557 8,910 Accruing loans past due 90 days or more — — — — — 291 3,628 — 3,919 Nonaccrual 5,722 544 551 214 52 253 35,103 311 42,750 Total other $ 100,193 175,407 74,197 47,822 8,640 33,770 958,934 2,892 $ 1,401,855 Total loans and leases at June 30, 2020 $ 14,810,789 16,179,761 11,519,760 8,136,036 6,816,987 21,445,766 17,346,363 1,502,086 $ 97,757,548 The following table summarizes the loan grades applied at December 31, 2019 to the various classes of the Company’s commercial loans and commercial real estate loans. Real Estate Commercial, Residential Other Financial, Builder and Commercial Leasing, etc. Commercial Developer Construction (In thousands) December 31, 2019 Pass $ 22,595,821 25,728,725 1,419,162 7,092,799 Criticized accrual 895,790 770,609 124,101 211,292 Criticized nonaccrual 346,557 158,474 3,982 32,770 Total $ 23,838,168 26,657,808 1,547,245 7,336,861 3. Loans and leases and the allowance for credit losses, continued Allowance for credit losses For purposes of determining the level of the allowance for credit losses, the Company evaluates its loan and lease portfolio by loan type. Changes in the allowance for credit losses for the three months ended June 30, 2020 were as follows: Commercial, Financial, Real Estate Leasing, etc. Commercial Residential Consumer Unallocated Total (In thousands) Beginning balance $ 358,092 433,689 115,792 476,793 — $ 1,384,366 Provision for credit losses 69,400 159,090 2,850 93,660 — 325,000 Net charge-offs Charge-offs (32,608 ) (17,472 ) (1,609 ) (39,708 ) — (91,397 ) Recoveries 3,373 1,014 1,888 13,992 — 20,267 Net (charge-offs) recoveries (29,235 ) (16,458 ) 279 (25,716 ) — (71,130 ) Ending balance $ 398,257 576,321 118,921 544,737 — $ 1,638,236 Changes in the allowance for credit losses for the three months ended June 30, 2019 were as follows: Commercial, Financial, Real Estate Leasing, etc. Commercial Residential Consumer Unallocated Total (In thousands) Beginning balance $ 335,620 337,995 65,136 203,045 77,541 $ 1,019,337 Provision for credit losses 10,337 14,501 (2,376 ) 31,594 944 55,000 Net charge-offs Charge-offs (16,608 ) (10,165 ) (3,263 ) (39,370 ) — (69,406 ) Recoveries 6,506 965 1,514 15,951 — 24,936 Net charge-offs (10,102 ) (9,200 ) (1,749 ) (23,419 ) — (44,470 ) Ending balance $ 335,855 343,296 61,011 211,220 78,485 $ 1,029,867 Changes in the allowance for credit losses for the six months ended June 30, 2020 were as follows: Commercial, Financial, Real Estate Leasing, etc. Commercial Residential Consumer Unallocated Total (In thousands) Beginning balance $ 366,094 322,201 56,033 229,118 77,625 $ 1,051,071 Adoption of new accounting standard (61,474 ) 23,656 53,896 194,004 (77,625 ) 132,457 Provision for credit losses 135,994 247,756 12,141 179,109 — 575,000 Net charge-offs Charge-offs (48,991 ) (18,744 ) (6,711 ) (84,655 ) — (159,101 ) Recoveries 6,634 1,452 3,562 27,161 — 38,809 Net charge-offs (42,357 ) (17,292 ) (3,149 ) (57,494 ) — (120,292 ) Ending balance $ 398,257 576,321 118,921 544,737 — $ 1,638,236 3. Loans and leases and the all owance for credit losses, continued Changes in the allowance for credit losses for the six months ended June 30, 2019 were as follows: Commercial, Financial, Real Estate Leasing, etc. Commercial Residential Consumer Unallocated Total (In thousands) Beginning balance $ 330,055 341,655 69,125 200,564 78,045 $ 1,019,444 Provision for credit losses 16,608 10,298 (4,823 ) 54,477 440 77,000 Net charge-offs Charge-offs (25,108 ) (10,448 ) (6,635 ) (72,315 ) — (114,506 ) Recoveries 14,300 1,791 3,344 28,494 — 47,929 Net charge-offs (10,808 ) (8,657 ) (3,291 ) (43,821 ) — (66,577 ) Ending balance $ 335,855 343,296 61,011 211,220 78,485 $ 1,029,867 Despite the allocation in the preceding tables, the allowance for credit losses is general in nature and is available to absorb losses from any loan or lease type. A description of the methodologies used by the Company to estimate its allowance for credit losses prior to January 1, 2020 is included in note 4 of Notes to Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019. In establishing the allowance for credit losses subsequent to December 31, 2019, the Company estimates losses attributable to specific troubled credits identified through both normal and targeted credit review processes and also estimates losses for loans and leases with similar risk characteristics on a collective basis. The amounts of specific loss components in the Company’s loan and lease portfolios are determined through a loan-by-loan analysis of larger balance commercial loans and commercial real estate loans that are in nonaccrual status. Such loss estimates are typically based on expected future cash flows, collateral values and other factors that may impact the borrower’s ability to pay. To the extent that those loans are collateral-dependent, they are evaluated based on the fair value of the loan’s collateral as estimated at or near the financial statement date. As the quality of a loan deteriorates to the point of classifying the loan as “criticized,” the process of obtaining updated collateral valuation information is usually initiated, unless it is not considered warranted given factors such as the relative size of the loan, the characteristics of the collateral or the age of the last valuation. In those cases where current appraisals may not yet be available, prior appraisals are utilized with adjustments, as deemed necessary, for estimates of subsequent declines in values as determined by line of business and/or loan workout personnel. Those adjustments are reviewed and assessed for reasonableness by the Company’s credit department. Accordingly, for real estate collateral securing larger nonaccrual commercial loans and commercial real estate loans, estimated collateral values are based on current appraisals and estimates of value. For non-real estate loans, collateral is assigned a discounted estimated liquidation value and, depending on the nature of the collateral, is verified through field exams or other procedures. In assessing collateral, real estate and non-real estate values are reduced by an estimate of selling costs. For residential real estate loans, including home equity loans and lines of credit, the excess of the loan balance over the net realizable value of the property collateralizing the loan is charged-off when the loan becomes 150 days delinquent. That charge-off is based on recent indications of value from external parties that are generally obtained shortly after a loan becomes nonaccrual. Loans to consumers that file for bankruptcy are generally charged-off to estimated net collateral value shortly after the Company is notified of such filings. When evaluating individual home equity loans and lines of credit for charge off and for purposes of estimating losses in determining the allowance for credit losses, the Company gives consideration to the required repayment of any first lien positions related to collateral property. Modified loans, including smaller balance homogenous loans, that are considered to be troubled debt restructurings are evaluated for impairment giving consideration to the impact of the modified loan terms on the present value of the loan’s expected cash flows. 3. Loans and leases and the allowance for credit losses, continued Information with respect to loans and leases that were considered nonaccrual at the beginning and end of the reporting period and the interest income recognized on such loans for the three-month and six-month periods ended June 30, 2020 and 2019 follows. June 30, 2020 March 31, 2020 January 1, 2020 Three Months Ended June 30, 2020 Six Months Ended June 30, 2020 Amortized Cost with Allowance Amortized Cost Total Amortized Cost Amortized Cost Interest Income Recognized Interest Income Recognized (In thousands) Commercial, financial, leasing, etc. $ 138,556 146,098 284,654 286,647 346,743 1,298 3,036 Real estate: Commercial 57,675 114,813 172,488 188,469 173,796 4,697 5,789 Residential builder and developer 1,748 — 1,748 3,204 4,708 11 59 Other commercial construction 42,969 42,457 85,426 34,935 35,881 5,716 6,577 Residential 80,772 226,135 306,907 293,638 322,504 5,029 11,848 Residential — limited documentation 26,460 92,235 118,695 119,317 114,667 256 457 Consumer: Home equity lines and loans 38,890 38,204 77,094 63,071 65,039 760 2,219 Recreational finance 16,264 7,888 24,152 13,405 14,308 154 306 Automobile 35,510 7,226 42,736 19,251 21,293 45 92 Other 7,747 35,003 42,750 39,811 35,394 161 315 Total $ 446,591 710,059 1,156,650 1,061,748 1,134,333 18,127 30,698 3. Loans and leases and the allowance for credit losses, continued June 30, 2019 March 31, 2019 January 1, 2019 Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Amortized Cost with Allowance Amortized Cost Total Amortized Cost Amortized Cost Interest Income Recognized Interest Income Recognized (In thousands) Commercial, financial, leasing, etc. $ 150,974 72,759 223,733 245,819 234,423 3,635 6,716 Real estate: Commercial 52,443 150,673 203,116 207,709 203,672 2,314 3,410 Residential builder and developer 1,429 4,556 5,985 4,392 4,798 35 219 Other commercial construction 25,572 7,197 32,769 19,899 22,205 544 1,181 Residential 57,323 153,599 210,922 210,266 233,352 2,990 6,589 Residential — limited documentation 25,796 61,755 87,551 84,863 84,685 274 526 Consumer: Home equity lines and loans 25,530 41,397 66,927 69,245 71,292 1,461 2,771 Recreational finance 6,493 4,660 11,153 10,972 11,199 142 284 Automobile 13,852 6,318 20,170 21,209 23,359 53 107 Other 2,757 301 3,058 7,237 4,623 125 247 Total $ 362,169 503,215 865,384 881,611 893,608 11,573 22,050 In determining the allowance for credit losses, accruing loans with similar risk characteristics are generally evaluated collectively. The Company utilizes statistically developed models to project principal balances over the remaining contractual lives of the loan portfolios and to determine estimated credit losses through a reasonable and supportable forecast period. Individual loan credit quality indicators including loan grade and borrower repayment performance inform the models, which have been statistically developed based on historical correlations of credit losses with prevailing economic metrics, including unemployment, gross domestic product and real estate prices. Model forecasts may be adjusted for inherent limitations or biases that have been identified through independent validation and back-testing of model performance to actual realized results. At both January 1 and June 30, 2020, the Company utilized a reasonable and supportable forecast period of two years. Subsequent to this forecast period the Company reverted, ratably over a one-year period, to historical loss experience to inform its estimate of losses for the remaining contractual life of each portfolio. The Company also considered the impact of portfolio concentrations, changes in underwriting practices, product expansions into new markets, imprecision in its economic forecasts, geopolitical conditions and other risk factors that might influence its loss estimation process. The Company’s reserve for off-balance sheet credit exposures was not material at June 30, 2020 and December 31, 2019. Loan modifications During the normal course of business, the Company modifies loans to maximize recovery efforts. If the borrower is experiencing financial difficulty and a concession is granted, the Company considers such modifications as troubled debt restructurings and classifies those loans as either nonaccrual loans or renegotiated loans. The types of concessions that the Company grants typically include principal deferrals and interest rate concessions, but may also include other types of concessions. 3. Loans and leases and the allowance for credit losses, continued The table that follows summarizes the Company’s loan modification activities that were considered troubled debt restructurings for the three-month and six-month periods ended June 30, 2020 and 2019: Post-modification (a) Number Pre- modification Recorded Investment Principal Deferral Interest Rate Reduction Other Combination of Concession Types Total Three Months Ended June 30, 2020 (Dollars in thousands) Commercial, financial, leasing, etc. 135 $ 55,136 $ 17,551 $ — $ 31,605 $ 5,514 $ 54,670 Real estate: Commercial 46 41,872 10,511 333 4,800 16,348 31,992 Residential builder and developer 1 91 — — — 90 90 Residential 25 8,872 3,101 — — 6,533 9,634 Residential — limited documentation — — — — — — — Consumer: Home equity lines and loans 120 7,571 147 — — 7,437 7,584 Recreational finance 271 10,795 10,795 — — — 10,795 Automobile 1,461 26,352 26,352 — — — 26,352 Other 335 2,183 682 — — 1,501 2,183 Total 2,394 $ 152,872 $ 69,139 $ 333 $ 36,405 $ 37,423 $ 143,300 Three Months Ended June 30, 2019 Commercial, financial, leasing, etc. 24 $ 2,597 $ 667 $ — $ — $ 1,891 $ 2,558 Real estate: Commercial 14 10,340 2,577 — — 7,641 10,218 Other commercial construction 1 1,038 — — 1,033 1,033 Residential 26 7,513 4,008 — — 4,034 8,042 Residential — limited documentation 2 612 160 — — 465 625 Consumer: Home equity lines and loans 13 1,273 53 — — 1,225 1,278 Recreational finance 1 15 15 — — — 15 Automobile 12 189 189 — — — 189 Total 93 $ 23,577 $ 7,669 $ — $ — $ 16,289 $ 23,958 3. Loans and leases and the allowance for credit losses, continued Post-modification (a) Number Pre- modification Recorded Investment Principal Deferral Interest Rate Reduction Other Combination of Concession Types Total Six Months Ended June 30, 2020 (Dollars in thousands) Commercial, financial, leasing, etc. 167 $ 67,828 $ 22,617 $ — $ 31,605 $ 12,501 $ 66,723 Real estate: Commercial 56 81,514 11,866 333 4,800 52,316 69,315 Residential builder and developer 1 91 — — — 90 90 Residential 52 19,050 6,348 — — 15,510 21,858 Residential — limited documentation 9 2,980 2,667 — — 1,232 3,899 Consumer: Home equity lines and loans 126 8,309 559 — — 7,771 8,330 Recreational finance 274 10,885 10,885 — — — 10,885 Automobile 1,470 26,534 26,534 — — — 26,534 Other 335 2,183 682 — — 1,501 2,183 Total 2,490 $ 219,374 $ 82,158 $ 333 $ 36,405 $ 90,921 $ 209,817 Six Months Ended June 30, 2019 Commercial, financial, leasing, etc. 89 $ 33,212 $ 7,141 $ — $ — $ 26,161 $ 33,302 Real estate: Commercial 29 19,581 3,564 — — 15,608 19,172 Residential builder and developer 2 1,330 1,068 — — — 1,068 Other commercial construction 2 1,456 — — 1,399 1,399 Residential 43 11,329 5,759 — — 6,307 12,066 Residential — limited documentation 3 848 399 — — 465 864 Consumer: Home equity lines and loans 20 1,749 90 — — 1,679 1,769 Recreational finance 5 103 103 — — — 103 Automobile 32 506 469 — — 37 506 Total 225 $ 70,114 $ 18,593 $ — $ — $ 51,656 $ 70,249 (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. The present value of interest rate concessions, discounted at the effective rate of the original loan, was not material. Troubled debt restructurings are evaluated for impairment giving consideration to the impact of the modified loan terms on the present value of the loan’s expected cash flows. Impairment of troubled debt restructurings that have subsequently defaulted may also be measured based on the loan’s observable market price or the fair value of collateral if the loan is collateral-dependent. Charge-offs may also be recognized on troubled debt restructurings that have subsequently defaulted. Loans that were modified as troubled debt restructurings during the twelve months ended June 30, 2020 and 2019 and for which there was a subsequent payment default during the six-month periods ended June 30, 2020 and 2019, respectively, were not material. The amount of foreclosed residential real estate property held by the Company was $59 million and $76 million at June 30, 2020 and December 31, 2019, respectively. There were $273 million and $402 million at June 30, 2020 and December 31, 2019, respectively, of loans secured by residential real estate that were in the process of foreclosure. Of all loans in the process of foreclosure at June 30, 2020, approximately 40% were government guaranteed.

Borrowings

Borrowings	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Borrowings	4. Borrowings M&T had $527 million of fixed and variable rate junior subordinated deferrable interest debentures ("Junior Subordinated Debentures") outstanding at June 30, 2020 that are held by various trusts that were issued in connection with the issuance by those trusts of preferred capital securities ("Capital Securities") and common securities ("Common Securities"). The proceeds from the issuances of the Capital Securities and the Common Securities were used by the trusts to purchase the Junior Subordinated Debentures. The Common Securities of each of those trusts are wholly owned by M&T and are the only class of each trust's securities possessing general voting powers. The Capital Securities represent preferred undivided interests in the assets of the corresponding trust. Under the Federal Reserve Board’s risk-based capital guidelines, the securities are includable in M&T’s Tier 2 regulatory capital. Holders of the Capital Securities receive preferential cumulative cash distributions unless M&T exercises its right to extend the payment of interest on the Junior Subordinated Debentures as allowed by the terms of each such debenture, in which case payment of distributions on the respective Capital Securities will be deferred for comparable periods. During an extended interest period, M&T may not pay dividends or distributions on, or repurchase, redeem or acquire any shares of its capital stock. In general, the agreements governing the Capital Securities, in the aggregate, provide a full, irrevocable and unconditional guarantee by M&T of the payment of distributions on, the redemption of, and any liquidation distribution with respect to the Capital Securities. The obligations under such guarantee and the Capital Securities are subordinate and junior in right of payment to all senior indebtedness of M&T. The Capital Securities will remain outstanding until the Junior Subordinated Debentures are repaid at maturity, are redeemed prior to maturity or are distributed in liquidation to the trusts. The Capital Securities are mandatorily redeemable in whole, but not in part, upon repayment at the stated maturity dates (ranging from 2027 to 2033) of the Junior Subordinated Debentures or the earlier redemption of the Junior Subordinated Debentures in whole upon the occurrence of one or more events set forth in the indentures relating to the Capital Securities, and in whole or in part at any time after an optional redemption prior to contractual maturity contemporaneously with the optional redemption of the related Junior Subordinated Debentures in whole or in part, subject to possible regulatory approval. Also included in long-term borrowings was an agreement to repurchase securities that totaled $100 million and $102 million at June 30, 2020 and December 31, 2019, respectively. The outstanding agreement matured in July 2020. The agreement was subject to legally enforceable master netting arrangements, however, the Company did not offset any amounts related to the agreement in its consolidated financial statements. The Company posted collateral consisting primarily of government guaranteed mortgage-backed securities of $107 million and $108 million at June 30, 2020 and December 31, 2019, respectively .

Revenue from contracts with cus

Revenue from contracts with customers	6 Months Ended
	Jun. 30, 2020
Revenue From Contract With Customer [Abstract]
Revenue from contracts with customers	5. Revenue from contracts with customers A significant amount of the Company’s revenues are derived from net interest income on financial assets and liabilities, mortgage banking revenues, trading account and foreign exchange gains, investment securities gains, loan and letter of credit fees, income from bank-owned life insurance, and certain other revenues that are generally excluded from the scope of accounting guidance for revenue from contracts with customers. For noninterest income revenue streams, the Company recognizes the expected amount of consideration as revenue when the performance obligations related to the services under the terms of a contract are satisfied. The Company’s contracts generally do not contain terms that necessitate significant judgment to determine the amount of revenue to recognize. The Company generally charges customer accounts or otherwise bills customers upon completion of its services. Typically the Company’s contracts with customers have a duration of one year or less and payment for services is received at least annually, but oftentimes more frequently as services are provided. At June 30, 2020 and 5. Revenue from contracts with customers, continued December 31, 2019, the Company had $60 million and $62 million, respectively, of amounts receivable related to recognized revenue from the sources in the accompanying tables. Such amounts are classified in accrued interest and other assets in the Company’s consolidated balance sheet. In certain situations the Company is paid in advance of providing services and defers the recognition of revenue until its service obligation is satisfied. At June 30, 2020 and December 31, 2019, the Company had deferred revenue of $42 million and $43 million, respectively, related to the sources in the accompanying tables recorded in accrued interest and other liabilities in the consolidated balance sheet. The following tables summarize sources of the Company’s noninterest income during the three-month and six-month periods ended June 30, 2020 and 2019 that are subject to the noted accounting guidance. Business Banking Commercial Banking Commercial Real Estate Discretionary Portfolio Residential Mortgage Banking Retail Banking All Other Total Three Months Ended June 30, 2020 (In thousands) Classification in consolidated statement of income Service charges on deposit accounts $ 11,271 22,514 2,565 — — 40,024 1,081 $ 77,455 Trust income 6 137 — — — — 151,739 151,882 Brokerage services income — — — — — — 10,463 10,463 Other revenues from operations: Merchant discount and credit card fees 8,159 8,891 379 — — 3,450 176 21,055 Other — 787 1,188 150 1,052 3,166 9,421 15,764 $ 19,436 32,329 4,132 150 1,052 46,640 172,880 $ 276,619 Three Months Ended June 30, 2019 Classification in consolidated statement of income Service charges on deposit accounts $ 15,175 23,094 2,362 — 2 65,661 1,493 $ 107,787 Trust income 7 224 — — — — 144,151 144,382 Brokerage services income — — — — — — 12,478 12,478 Other revenues from operations: Merchant discount and credit card fees 9,895 13,129 496 — — 4,566 602 28,688 Other — 3,145 2,680 641 1,033 9,329 8,595 25,423 $ 25,077 39,592 5,538 641 1,035 79,556 167,319 $ 318,758 5. Revenue from contracts with customers, continued Business Banking Commercial Banking Commercial Real Estate Discretionary Portfolio Residential Mortgage Banking Retail Banking All Other Total Six Months Ended June 30, 2020 (In thousands) Classification in consolidated statement of income Service charges on deposit accounts $ 26,521 46,671 5,377 — — 101,694 3,353 $ 183,616 Trust income 18 441 — — — — 300,174 300,633 Brokerage services income — — — — — — 23,592 23,592 Other revenues from operations: Merchant discount and credit card fees 18,490 22,207 1,228 — — 5,721 576 48,222 Other — 2,973 2,031 1,007 1,974 9,148 21,937 39,070 $ 45,029 72,292 8,636 1,007 1,974 116,563 349,632 $ 595,133 Six Months Ended June 30, 2019 Classification in consolidated statement of income Service charges on deposit accounts $ 30,284 46,304 4,888 — 4 126,812 2,607 $ 210,899 Trust income 12 438 — — — — 276,718 277,168 Brokerage services income — — — — — — 24,954 24,954 Other revenues from operations: Merchant discount and credit card fees 18,777 25,221 1,102 — — 7,704 1,022 53,826 Other — 4,147 4,468 1,042 2,097 17,823 19,083 48,660 $ 49,073 76,110 10,458 1,042 2,101 152,339 324,384 $ 615,507

Pension plans and other postret

Pension plans and other postretirement benefits	6 Months Ended
	Jun. 30, 2020
Compensation And Retirement Disclosure [Abstract]
Pension plans and other postretirement benefits	6. Pension plans and other postretirement benefits The Company provides defined benefit pension and other postretirement benefits (including health care and life insurance benefits) to qualified retired employees. Net periodic defined benefit cost for defined benefit plans consisted of the following: Pension Benefits Other Postretirement Benefits Three Months Ended June 30 2020 2019 2020 2019 (In thousands) Service cost $ 5,258 4,559 262 229 Interest cost on projected benefit obligation 17,824 20,590 451 569 Expected return on plan assets (31,281 ) (30,470 ) — — Amortization of prior service cost (credit) 154 154 (1,194 ) (1,190 ) Amortization of net actuarial loss (gain) 15,098 6,546 (318 ) (323 ) Net periodic cost (benefit) $ 7,053 1,379 (799 ) (715 ) Pension Benefits Other Postretirement Benefits Six Months Ended June 30 2020 2019 2020 2019 (In thousands) Service cost $ 9,972 8,646 485 429 Interest cost on projected benefit obligation 35,710 40,790 870 1,172 Expected return on plan assets (62,756 ) (61,070 ) — — Amortization of prior service cost (credit) 279 279 (2,369 ) (2,365 ) Amortization of net actuarial loss (gain) 29,048 10,996 (618 ) (623 ) Net periodic cost (benefit) $ 12,253 (359 ) (1,632 ) (1,387 ) Service cost is reflected in salaries and employee benefits expense in the consolidated statement of income. The other components of net periodic benefit cost are reflected in other costs of operations. Expenses incurred in connection with the Company's defined contribution pension and retirement savings plans totaled $23 million and $19 million for the three months ended June 30, 2020 and 2019, respectively, and $51 million and $41 million for the six months ended June 30, 2020 and 2019, respectively, and are included in salaries and employee benefits expense.

Earnings per common share

Earnings per common share	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Earnings per common share	7. Earnings per common share The computations of basic earnings per common share follow: Three Months Ended June 30 Six Months Ended June 30 2020 2019 2020 2019 (In thousands, except per share) Income available to common shareholders: Net income $ 241,054 473,260 509,876 956,002 Less: Preferred stock dividends (17,050 ) (18,130 ) (34,128 ) (36,260 ) Net income available to common equity 224,004 455,130 475,748 919,742 Less: Income attributable to unvested stock-based compensation awards (906 ) (2,498 ) (1,954 ) (5,024 ) Net income available to common shareholders $ 223,098 452,632 473,794 914,718 Weighted-average shares outstanding: Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards 129,059 136,182 129,750 137,403 Less: Unvested stock-based compensation awards (784 ) (749 ) (764 ) (749 ) Weighted-average shares outstanding 128,275 135,433 128,986 136,654 Basic earnings per common share $ 1.74 3.34 3.67 6.69 The computations of diluted earnings per common share follow: Three Months Ended June 30 Six Months Ended June 30 2020 2019 2020 2019 (In thousands, except per share) Net income available to common equity $ 224,004 455,130 475,748 919,742 Less: Income attributable to unvested stock-based compensation awards (905 ) (2,497 ) (1,953 ) (5,023 ) Net income available to common shareholders $ 223,099 452,633 473,795 914,719 Adjusted weighted-average shares outstanding: Common and unvested stock-based compensation awards 129,059 136,182 129,750 137,403 Less: Unvested stock-based compensation awards (784 ) (749 ) (764 ) (749 ) Plus: Incremental shares from assumed conversion of stock-based compensation awards and warrants to purchase common stock 58 31 58 31 Adjusted weighted-average shares outstanding 128,333 135,464 129,044 136,685 Diluted earnings per common share $ 1.74 3.34 3.67 6.69 GAAP defines unvested share-based awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) as participating securities that shall be included in the computation of earnings per common share pursuant to the two-class method. The Company has issued stock-based compensation awards in the form of restricted stock and restricted stock units which, in accordance with GAAP, are considered participating securities. Stock-based compensation awards and warrants to purchase common stock of M&T representing 483,491 and 115,293 common shares during the three-month periods ended June 30, 2020 and 2019, respectively, and 474,093 and 197,598 common shares during the six-month periods ended June 30, 2020 and 2019, respectively were not included in the computations of diluted earnings per common share because the effect on those periods would have been antidilutive.

Comprehensive income

Comprehensive income	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Comprehensive income	8. Comprehensive income The following tables display the components of other comprehensive income (loss) and amounts reclassified from accumulated other comprehensive income (loss) to net income: Investment Defined Benefit Total Amount Income Securities Plans Other Before Tax Tax Net (In thousands) Balance — January 1, 2020 $ 50,701 (464,548 ) 133,888 $ (279,959 ) 73,279 $ (206,680 ) Other comprehensive income before reclassifications: Unrealized holding gains, net 177,086 — — 177,086 (45,856 ) 131,230 Foreign currency translation adjustment — — (3,624 ) (3,624 ) 630 (2,994 ) Unrealized gains on cash flow hedges — — 511,195 511,195 (132,404 ) 378,791 Total other comprehensive income before reclassifications 177,086 — 507,571 684,657 (177,630 ) 507,027 Amounts reclassified from accumulated other comprehensive income that (increase) decrease net income: Amortization of unrealized holding losses on held-to-maturity (“HTM”) securities 1,619 — — 1,619 (a) (450 ) 1,169 Accretion of net gain on terminated cash flow hedges — — (64 ) (64 ) (c) 18 (46 ) Net yield adjustment from cash flow hedges currently in effect — — (101,194 ) (101,194 ) (a) 26,210 (74,984 ) Amortization of prior service credit — (2,090 ) — (2,090 ) (d) 650 (1,440 ) Amortization of actuarial losses — 28,430 — 28,430 (d) (8,846 ) 19,584 Total other comprehensive income 178,705 26,340 406,313 611,358 (160,048 ) 451,310 Balance — June 30, 2020 $ 229,406 (438,208 ) 540,201 $ 331,399 (86,769 ) $ 244,630 Balance — January 1, 2019 $ (200,107 ) (354,502 ) (14,719 ) $ (569,328 ) 149,247 $ (420,081 ) Other comprehensive income before reclassifications: Unrealized holding gains, net 207,802 — — 207,802 (54,609 ) 153,193 Foreign currency translation adjustment — — (507 ) (507 ) 107 (400 ) Unrealized gains on cash flow hedges — — 188,272 188,272 (49,497 ) 138,775 Total other comprehensive income before reclassifications 207,802 — 187,765 395,567 (103,999 ) 291,568 Amounts reclassified from accumulated other comprehensive income that (increase) decrease net income: Amortization of unrealized holding losses on HTM securities 1,691 — — 1,691 (a) (445 ) 1,246 Losses realized in net income 7 — — 7 (b) (2 ) 5 Accretion of net gain on terminated cash flow hedges — — (56 ) (56 ) (c) 14 (42 ) Net yield adjustment from cash flow hedges currently in effect — — 11,176 11,176 (a) (2,938 ) 8,238 Amortization of prior service credit — (2,086 ) — (2,086 ) (d) 548 (1,538 ) Amortization of actuarial losses — 10,373 — 10,373 (d) (2,727 ) 7,646 Total other comprehensive income 209,500 8,287 198,885 416,672 (109,549 ) 307,123 Balance — June 30, 2019 $ 9,393 (346,215 ) 184,166 $ (152,656 ) 39,698 $ (112,958 ) (a) Included in interest income. (b) Included in gain (loss) on bank investment securities. (c) Included in interest expense. (d) Included in other costs of operations. 8. Comprehensive income, continued Accumulated other comprehensive income (loss), net consisted of the following: Defined Cash Flow Investment Benefit Hedges Securities Plans and Total (In thousands) Balance — December 31, 2019 $ 37,380 (342,419 ) 98,359 $ (206,680 ) Net gain during period 132,399 18,144 300,767 451,310 Balance — June 30, 2020 $ 169,779 (324,275 ) 399,126 $ 244,630

Derivative financial instrument

Derivative financial instruments	6 Months Ended
	Jun. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative financial instruments	9. Derivative financial instruments As part of managing interest rate risk, the Company enters into interest rate swap agreements to modify the repricing characteristics of certain portions of the Company’s portfolios of earning assets and interest-bearing liabilities. The Company designates interest rate swap agreements utilized in the management of interest rate risk as either fair value hedges or cash flow hedges. Interest rate swap agreements are generally entered into with counterparties that meet established credit standards and most contain master netting, collateral and/or settlement provisions protecting the at-risk party. Based on adherence to the Company’s credit standards and the presence of the netting, collateral or settlement provisions, the Company believes that the credit risk inherent in these contracts was not material as of June 30, 2020. The net effect of interest rate swap agreements was to increase net interest income by $81 million and $117 million during the three-month and six-month periods ended June 30, 2020, respectively, and to decrease net interest income by $11 million and $24 million during the three-month and six-month periods ended June 30, 2019, respectively. Information about interest rate swap agreements entered into for interest rate risk management purposes summarized by type of financial instrument the swap agreements were intended to hedge follows: Weighted- Estimated Notional Average Average Rate Fair Value Amount Maturity Fixed Variable Gain (In thousands) (In (In June 30, 2020 Fair value hedges: Fixed rate long-term borrowings (b) $ 3,050,000 2.2 2.61 % .72 % $ (469 ) Cash flow hedges: Interest payments on variable rate commercial real estate loans (b)(c) 54,250,000 1.3 2.55 % .18 % 220 Total $ 57,300,000 1.3 $ (249 ) December 31, 2019 Fair value hedges: Fixed rate long-term borrowings (b) $ 3,800,000 2.2 2.51 % 2.27 % $ (567 ) Cash flow hedges: Interest payments on variable rate commercial real estate loans (b)(d) 53,750,000 1.4 2.44 % 1.73 % (1,195 ) Total $ 57,550,000 1.5 $ (1,762 ) (a) Certain clearinghouse exchanges consider payments by counterparties for variation margin on derivative instruments to be settlements of those positions. The impact of such treatment at June 30, 2020 and December 31, 2019 was a reduction of the estimated fair value gains on interest rate swap agreements designated as fair value hedges of $133.8 million and $45.1 million, respectively, and on interest rate swap agreements designated as cash flow hedges of $549.3 million and $140.7 million, respectively. (b) Under the terms of these agreements, the Company receives settlement amounts at a fixed rate and pays at a variable rate. (c) (d) . 9. Derivative financial instruments, continued The Company utilizes commitments to sell residential and commercial real estate loans to hedge the exposure to changes in the fair value of real estate loans held for sale. Such commitments have generally been designated as fair value hedges. The Company also utilizes commitments to sell real estate loans to offset the exposure to changes in fair value of certain commitments to originate real estate loans for sale. Derivative financial instruments used for trading account purposes included interest rate contracts, foreign exchange and other option contracts, foreign exchange forward and spot contracts, and financial futures. Interest rate contracts entered into for trading account purposes had notional values of $37.1 billion and $48.6 billion at June 30, 2020 and December 31, 2019, respectively. The notional amounts of foreign currency and other option and futures contracts entered into for trading account purposes aggregated $1.0 billion and $1.2 billion at June 30, 2020 and December 31, 2019, respectively. Information about the fair values of derivative instruments in the Company’s consolidated balance sheet and consolidated statement of income follows: Asset Derivatives Liability Derivatives Fair Value Fair Value June 30, December 31, June 30, December 31, 2020 2019 2020 2019 (In thousands) Derivatives designated and qualifying as hedging instruments Interest rate swap agreements (a) $ 818 $ 232 $ 1,067 $ 1,994 Commitments to sell real estate loans (a) 2,473 1,195 7,763 421 3,291 1,427 8,830 2,415 Derivatives not designated and qualifying as hedging instruments Mortgage-related commitments to originate real estate loans for sale (a) 40,727 11,965 621 1,225 Commitments to sell real estate loans (a) 2,253 3,074 7,526 3,548 Trading: Interest rate contracts (b) 1,231,484 398,295 127,008 68,103 Foreign exchange and other option and futures contracts (b) 12,925 12,506 10,986 11,800 1,287,389 425,840 146,141 84,676 Total derivatives $ 1,290,680 $ 427,267 $ 154,971 $ 87,091 (a) Asset derivatives are reported in other assets and liability derivatives are reported in other liabilities. (b) Asset derivatives are reported in trading account assets and liability derivatives are reported in other liabilities. The impact of variation margin payments at June 30, 2020 and December 31, 2019 was a reduction of the estimated fair value of interest rate contracts in the trading account in an asset position of $3.1 million and $43.3 million, respectively, and in a liability position of $1.0 billion and $281.3 million, respectively. Amount of Gain (Loss) Recognized Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Derivative Hedged Item Derivative Hedged Item (In thousands) Derivatives in fair value hedging relationships Interest rate swap agreements: Fixed rate long-term borrowings (a) $ 117 (605 ) $ 56,679 (56,458 ) Derivatives not designated as hedging instruments Trading: Interest rate contracts (b) $ 978 $ 8,493 Foreign exchange and other option and futures contracts (b) 717 2,479 Total $ 1,695 $ 10,972 9. Derivative financial instruments, continued Amount of Gain (Loss) Recognized Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Derivative Hedged Item Derivative Hedged Item (In thousands) Derivatives in fair value hedging relationships Interest rate swap agreements: Fixed rate long-term borrowings (a) $ 88,827 (88,429 ) $ 90,859 (90,472 ) Derivatives not designated as hedging instruments Trading: Interest rate contracts (b) $ 13,764 $ 11,204 Foreign exchange and other option and futures contracts (b) 5,069 4,092 Total $ 18,833 $ 15,296 (a) Reported as an adjustment to interest expense. (b) Reported as trading account and foreign exchange gains. Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount of the Hedged Item June 30, 2020 December 31, 2019 June 30, 2020 December 31, 2019 (In thousands) Location in the of the Hedged Items in Fair Value Long-term debt $ 3,180,022 $ 3,840,775 $ 132,069 $ 43,640 The amount of gain (loss) recognized in the consolidated statement of income associated with derivatives designated as cash flow hedges was not material. The Company also has commitments to sell and commitments to originate residential and commercial real estate loans that are considered derivatives. The Company designates certain of the commitments to sell real estate loans as fair value hedges of real estate loans held for sale. The Company also utilizes commitments to sell real estate loans to offset the exposure to changes in the fair value of certain commitments to originate real estate loans for sale. As a result of these activities, net unrealized pre-tax gains related to hedged loans held for sale, commitments to originate loans for sale and commitments to sell loans were approximately $57 million and $18 million at June 30, 2020 and December 31, 2019, respectively. Changes in unrealized gains and losses are included in mortgage banking revenues and, in general, are realized in subsequent periods as the related loans are sold and commitments satisfied. The Company does not offset derivative asset and liability positions in its consolidated financial statements. The Company’s exposure to credit risk by entering into derivative contracts is mitigated through master netting agreements and collateral posting or settlement requirements. Master netting agreements covering interest rate and foreign exchange contracts with the same party include a right to set-off that becomes enforceable in the event of default, early termination or under other specific conditions. 9. Derivative financial instruments, continued The aggregate fair value of derivative financial instruments in a liability position and the net liability positions with counterparties, which are subject to enforceable master netting arrangements, was $143 million and $51 million at June 30, 2020 and December 31, 2019, respectively. The Company was required to post collateral relating to those positions of $139 million and $50 million at June 30, 2020 and December 31, 2019, respectively. Certain of the Company’s derivative financial instruments contain provisions that require the Company to maintain specific credit ratings from credit rating agencies to avoid higher collateral posting requirements. If the Company’s debt rating were to fall below specified ratings, the counterparties of the derivative financial instruments could demand immediate incremental collateralization on those instruments in a net liability position. The aggregate fair value of all derivative financial instruments with such credit risk-related contingent features in a net liability position on June 30, 2020 was not significant. The aggregate fair value of derivative financial instruments in an asset position and the net asset positions with counterparties, which are subject to enforceable master netting arrangements, was $1 million and $6 million at June 30, 2020 and December 31, 2019, respectively. Counterparties posted collateral relating to those positions of $81 thousand and $5 million at June 30, 2020 and December 31, 2019, respectively. Trading account interest rate swap agreements entered into with customers are subject to the Company’s credit risk standards and often contain collateral provisions. In addition to the derivative contracts noted above, the Company clears certain derivative transactions through a clearinghouse, rather than directly with counterparties. Those transactions cleared through a clearinghouse require initial margin collateral and variation margin payments depending on the contracts being in a net asset or liability position. The amount of initial margin collateral posted by the Company was $124 million and $84 million at June 30, 2020 and December 31, 2019, respectively. The fair value asset and liability amounts of derivative contracts have been reduced by variation margin payments treated as settlements as described herein. Variation margin on derivative contracts not treated as settlements continues to represent collateral posted or received by the Company.

Variable interest entities and

Variable interest entities and asset securitizations	6 Months Ended
	Jun. 30, 2020
Text Block [Abstract]
Variable interest entities and asset securitizations	10. Variable interest entities and asset securitizations The Company’s securitization activity has consisted of securitizing loans originated for sale into government issued or guaranteed mortgage-backed securities. The amounts of those securitizations during the six-month periods ended June 30, 2020 and 2019 are presented in the Company’s consolidated statement of cash flows. The Company has not recognized any losses as a result of having securitized assets. As described in note 4, M&T has issued junior subordinated debentures payable to various trusts that have issued Capital Securities. M&T owns the common securities of those trust entities. The Company is not considered to be the primary beneficiary of those entities and, accordingly, the trusts are not included in the Company’s consolidated financial statements. At each of June 30, 2020 and December 31, 2019, the Company included the junior subordinated debentures as “long-term borrowings” in its consolidated balance sheet and recognized $23 million in other assets for its “investment” in the common securities of the trusts that will be concomitantly repaid to M&T by the respective trust from the proceeds of M&T’s repayment of the junior subordinated debentures associated with preferred capital securities described in note 4. 10. Variable interest entities and asset securitizations, continued The Company has invested as a limited partner in various partnerships that collectively had total assets of approximately $2.0 billion at June 30, 2020 and $1.5 billion at December 31, 2019. Those partnerships generally construct or acquire properties for which the investing partners are eligible to receive certain federal income tax credits in accordance with government guidelines. Such investments may also provide tax deductible losses to the partners. The partnership investments also assist the Company in achieving its community reinvestment initiatives. As a limited partner, there is no recourse to the Company by creditors of the partnerships. However, the tax credits that result from the Company’s investments in such partnerships are generally subject to recapture should a partnership fail to comply with the respective government regulations. The Company’s carrying amount of its investments in such partnerships was $745 million, including $363 million of unfunded commitments, at June 30, 2020 and $748 million, including $414 million of unfunded commitments, at December 31, 2019. Contingent commitments to provide additional capital contributions to these partnerships were not material at June 30, 2020. The Company has not provided financial or other support to the partnerships that was not contractually required. The Company’s maximum exposure to loss from its investments in such partnerships as of June 30, 2020 was $957 million, including possible recapture of certain tax credits. Management currently estimates that no material losses are probable as a result of the Company’s involvement with such entities. The Company, in its position as limited partner, does not direct the activities that most significantly impact the economic performance of the partnerships and, therefore, in accordance with the accounting provisions for variable interest entities, the partnership entities are not included in the Company’s consolidated financial statements. The Company’s investment in qualified affordable housing projects is amortized to income taxes in the consolidated statement of income as tax credits and other tax benefits resulting from deductible losses associated with the projects are received. The Company serves as investment advisor for certain registered money-market funds. The Company has no explicit arrangement to provide support to those funds, but may waive portions of its allowable management fees as a result of market conditions .

Fair value measurements

Fair value measurements	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair value measurements	11. Fair value measurements GAAP permits an entity to choose to measure eligible financial instruments and other items at fair value. The Company has not made any fair value elections at June 30, 2020. Pursuant to GAAP, fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. A three-level hierarchy exists in GAAP for fair value measurements based upon the inputs to the valuation of an asset or liability. • Level 1 — Valuation is based on quoted prices in active markets for identical assets and liabilities. • Level 2 — Valuation is determined from quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar instruments in markets that are not active or by model-based techniques in which all significant inputs are observable in the market. • Level 3 — Valuation is derived from model-based and other techniques in which at least one significant input is unobservable and which may be based on the Company's own estimates about the assumptions that market participants would use to value the asset or liability. When available, the Company attempts to use quoted market prices in active markets to determine fair value and classifies such items as Level 1 or Level 2. If quoted market prices in active markets are not available, fair value is often determined using model-based techniques incorporating various assumptions including interest rates, prepayment speeds and credit losses. Assets and liabilities valued using model-based techniques are classified as either Level 2 or Level 3, depending on the lowest level classification of an input that is considered significant to the overall 11. Fair value measurements, continued valuation. The following is a description of the valuation methodologies used for the Company's assets and liabilities that are measured on a recurring basis at estimated fair value. Trading account assets and liabilities Trading account assets and liabilities consist primarily of interest rate contracts and foreign exchange contracts with customers who require such services with offsetting positions with third parties to minimize the Company's risk with respect to such transactions. The Company generally determines the fair value of its derivative trading account assets and liabilities using externally developed pricing models based on market observable inputs and, therefore, classifies such valuations as Level 2. Mutual funds held in connection with deferred compensation and other arrangements have been classified as Level 1 valuations. Valuations of investments in municipal and other bonds can generally be obtained through reference to quoted prices in less active markets for the same or similar securities or through model-based techniques in which all significant inputs are observable and, therefore, such valuations have been classified as Level 2. Investment securities available for sale and equity securities The majority of the Company's available-for-sale investment securities have been valued by reference to prices for similar securities or through model-based techniques in which all significant inputs are observable and, therefore, such valuations have been classified as Level 2. Certain investments in mutual funds and equity securities are actively traded and, therefore, have been classified as Level 1 valuations. Real estate loans held for sale The Company utilizes commitments to sell real estate loans to hedge the exposure to changes in fair value of real estate loans held for sale. The carrying value of hedged real estate loans held for sale includes changes in estimated fair value during the hedge period. Typically, the Company attempts to hedge real estate loans held for sale from the date of close through the sale date. The fair value of hedged real estate loans held for sale is generally calculated by reference to quoted prices in secondary markets for commitments to sell real estate loans with similar characteristics and, accordingly, such loans have been classified as a Level 2 valuation. Commitments to originate real estate loans for sale and commitments to sell real estate loans The Company enters into various commitments to originate real estate loans for sale and commitments to sell real estate loans. Such commitments are considered to be derivative financial instruments and, therefore, are carried at estimated fair value on the consolidated balance sheet. The estimated fair values of such commitments were generally calculated by reference to quoted prices in secondary markets for commitments to sell real estate loans to certain government-sponsored entities and other parties. The fair valuations of commitments to sell real estate loans generally result in a Level 2 classification. The estimated fair value of commitments to originate real estate loans for sale are adjusted to reflect the Company's anticipated commitment expirations. The estimated commitment expirations are considered significant unobservable inputs contributing to the Level 3 classification of commitments to originate real estate loans for sale. Significant unobservable inputs used in the determination of estimated fair value of commitments to originate real estate loans for sale are included in the accompanying table of significant unobservable inputs to Level 3 measurements. Interest rate swap agreements used for interest rate risk management The Company utilizes interest rate swap agreements as part of the management of interest rate risk to modify the repricing characteristics of certain portions of its portfolios of earning assets and interest-bearing liabilities. The Company generally determines the fair value of its interest rate swap agreements using externally developed pricing models based on market observable inputs and, therefore, classifies such valuations as Level 2. The Company has 11. Fair value measurements, continued considered counterparty credit risk in the valuation of its interest rate swap agreement assets and has considered its own credit risk in the valuation of its interest rate swap agreement liabilities. The following tables present assets and liabilities at June 30, 2020 and December 31, 2019 measured at estimated fair value on a recurring basis: Fair Value Measurements Level 1 Level 2 Level 3 (In thousands) June 30, 2020 Trading account assets $ 1,293,534 $ 48,741 $ 1,244,793 $ — Investment securities available for sale: U.S. Treasury and federal agencies 9,893 — 9,893 — Obligations of states and political subdivisions 511 — 511 — Mortgage-backed securities: Government issued or guaranteed 5,690,161 — 5,690,161 — Privately issued 16 — — 16 Other debt securities 120,693 — 120,693 — 5,821,274 — 5,821,258 16 Equity securities 93,611 67,888 25,723 — Real estate loans held for sale 695,969 — 695,969 — Other assets (a) 46,271 — 5,544 40,727 Total assets $ 7,950,659 $ 116,629 $ 7,793,287 $ 40,743 Trading account liabilities $ 137,994 $ — $ 137,994 $ — Other liabilities (a) 16,977 — 16,356 621 Total liabilities $ 154,971 $ — $ 154,350 $ 621 December 31, 2019 Trading account assets $ 470,129 $ 49,040 $ 421,089 $ — Investment securities available for sale: U.S. Treasury and federal agencies 9,767 — 9,767 — Obligations of states and political subdivisions 775 — 775 — Mortgage-backed securities: Government issued or guaranteed 6,180,940 — 6,180,940 — Privately issued 16 — — 16 Other debt securities 127,278 — 127,278 — 6,318,776 — 6,318,760 16 Equity securities 140,041 100,637 39,404 — Real estate loans held for sale 442,079 — 442,079 — Other assets (a) 16,466 — 4,501 11,965 Total assets $ 7,387,491 $ 149,677 $ 7,225,833 $ 11,981 Trading account liabilities $ 79,903 $ — $ 79,903 $ — Other liabilities (a) 7,188 — 5,963 1,225 Total liabilities $ 87,091 $ — $ 85,866 $ 1,225 (a) Comprised predominantly of interest rate swap agreements used for interest rate risk management (Level 2), commitments to sell real estate loans (Level 2) and commitments to originate real estate loans to be held for sale (Level 3). 11. Fair value measurements, continued The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the three months ended June 30, 2020 and 2019 were as follows: Investment Securities Available for Sale Privately Issued Mortgage-Backed Other Assets 2020 (In thousands) Balance — March 31, 2020 $ 16 35,027 Total gains realized/unrealized: Included in earnings — 48,732 (a) Settlements — — Transfers out of Level 3 — (43,653 ) (b) Balance — June 30, 2020 $ 16 40,106 Changes in unrealized gains included in earnings related to assets still held at June 30, 2020 $ — 33,725 (a) 2019 Balance — March 31, 2019 $ 16 7,433 Total gains realized/unrealized: Included in earnings — 36,463 (a) Settlements — — Transfers out of Level 3 — (26,696 ) (b) Balance — June 30, 2019 $ 16 17,200 Changes in unrealized gains included in earnings related to assets still held at June 30, 2019 $ — 17,464 (a) 11. Fair value measurements, continued The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the six months ended June 30, 2020 and 2019 were as follows: Investment Securities Available for Sale Privately Issued Mortgage-Backed Other Assets 2020 (In thousands) Balance — January 1, 2020 $ 16 10,740 Total gains realized/unrealized: Included in earnings — 92,813 (a) Settlements — — Transfers out of Level 3 — (63,447 ) (b) Balance — June 30, 2020 $ 16 40,106 Changes in unrealized gains included in earnings related to assets still held at June 30, 2020 $ — 38,514 (a) 2019 Balance — January 1, 2019 $ 22 7,712 Total gains realized/unrealized: Included in earnings — 53,009 (a) Settlements (6 ) — Transfers out of Level 3 — (43,521 ) (b) Balance — June 30, 2019 $ 16 17,200 Changes in unrealized gains included in earnings related to assets still held at June 30, 2019 $ — 17,372 (a) (a) Reported as mortgage banking revenues in the consolidated statement of income and includes the fair value of commitment issuances and expirations. (b) Transfers out of Level 3 consist of interest rate locks transferred to closed loans. The Company is required, on a nonrecurring basis, to adjust the carrying value of certain assets or provide valuation allowances related to certain assets using fair value measurements. The more significant of those assets follow. Loans Loans are generally not recorded at fair value on a recurring basis. Periodically, the Company records nonrecurring adjustments to the carrying value of loans based on fair value measurements for partial charge-offs of the uncollectible portions of those loans. Nonrecurring adjustments also include certain impairment amounts for collateral-dependent loans when establishing the allowance for credit losses. Such amounts are generally based on the fair value of the underlying collateral supporting the loan and, as a result, the carrying value of the loan less the calculated valuation amount does not necessarily represent the fair value of the loan. Real estate collateral is typically valued using appraisals or other indications of value based on recent comparable sales of similar properties or assumptions generally observable in the marketplace and the related nonrecurring fair value measurement adjustments have been classified as Level 2, unless significant adjustments have been made to the valuation that are not readily observable by market participants. Non-real estate collateral supporting commercial loans generally consists of business assets such as receivables, inventory and equipment. Fair value estimations are typically determined by discounting recorded values of those assets to reflect estimated net realizable value considering specific borrower facts and circumstances and the experience of credit personnel in their dealings with similar borrower collateral liquidations. Such discounts were in 11. Fa ir value measurements, continued the range of 15% to 90% with a weighted-average of 56% at June 30, 2020. As these discounts are not readily observable and are considered significant, the valuations have been classified as Level 3. Automobile collateral is typically valued by reference to independent pricing sources based on recent sales transactions of similar vehicles, and the related nonrecurring fair value measurement adjustments have been classified as Level 2. Collateral values for other consumer installment loans are generally estimated based on historical recovery rates for similar types of loans, which at June 30, 2020 was 49%. As these recovery rates are not readily observable by market participants, such valuation adjustments have been classified as Level 3. Loans subject to nonrecurring fair value measurement were $248 million at June 30, 2020 ($145 million and $103 million of which were classified as Level 2 and Level 3, respectively), $305 million at December 31, 2019 ($115 million and $190 million of which were classified as Level 2 and Level 3, respectively) and $212 million at June 30, 2019 ($155 million and $57 million of which were classified as Level 2 and Level 3, respectively). Changes in fair value recognized for partial charge-offs of loans and loan impairment reserves on loans held by the Company on June 30, 2020 were decreases of $50 million for the three-month and six-month periods ended June 30, 2020. Changes in fair value recognized for partial charge-offs of loans and loan impairment reserves on loans held by the Company on June 30, 2019 were decreases of $20 million and $36 million for the three-month and six-month periods ended June 30, 2019, respectively. Assets taken in foreclosure of defaulted loans Assets taken in foreclosure of defaulted loans are primarily comprised of commercial and residential real property and are generally measured at the lower of cost or fair value less costs to sell. The fair value of the real property is generally determined using appraisals or other indications of value based on recent comparable sales of similar properties or assumptions generally observable in the marketplace, and the related nonrecurring fair value measurement adjustments have generally been classified as Level 2. Assets taken in foreclosure of defaulted loans subject to nonrecurring fair value measurement were $31 million and $17 million at June 30, 2020 and 2019, respectively. Changes in fair value recognized for those foreclosed assets held by the Company were not material during the three-month and six-month periods ended June 30, 2020 and 2019. Capitalized servicing rights Capitalized servicing rights are initially measured at fair value in the Company’s consolidated balance sheet. The Company utilizes the amortization method to subsequently measure its capitalized servicing assets. In accordance with GAAP, the Company must record impairment charges, on a nonrecurring basis, when the carrying value of certain strata exceed their estimated fair value. To estimate the fair value of servicing rights, the Company considers market prices for similar assets, if available, and the present value of expected future cash flows associated with the servicing rights calculated using assumptions that market participants would use in estimating future servicing income and expense. Such assumptions include estimates of the cost of servicing loans, loan default rates, an appropriate discount rate, and prepayment speeds. For purposes of evaluating and measuring impairment of capitalized servicing rights, the Company stratifies such assets based on the predominant risk characteristics of the underlying financial instruments that are expected to have the most impact on projected prepayments, cost of servicing and other factors affecting future cash flows associated with the servicing rights. Such factors may include financial asset or loan type, note rate and term. The amount of impairment recognized is the amount by which the carrying value of the capitalized servicing rights for a stratum exceed estimated fair value. Impairment is recognized through a valuation allowance. The determination of fair value of capitalized servicing rights is considered a Level 3 valuation. Capitalized servicing rights related to residential mortgage loans of $177 million and $188 million at June 30, 2020 and December 31, 2019, respectively, required a valuation allowance of $27 million and $7 million, respectively. Significant unobservable inputs used in this Level 3 valuation included weighted-average prepayment speeds of 18.03% and 18.50% at June 30, 2020 and December 31, 2019, respectively, and a weighted-average option-adjusted spread of 900 basis points at each date. Changes in fair value recognized for impairment of capitalized servicing rights were $10 million and $20 million during the three months and six months ended June 30, 2020, respetively. Changes in fair value recognized for impairment of capitalized servicing rights were $9 million during the three months and six months ended June 30, 2019. 11. Fair value measurements, continued Significant unobservable inputs to Level 3 measurements The following tables present quantitative information about significant unobservable inputs used in the fair value measurements for certain Level 3 assets and liabilities at June 30, 2020 and December 31, 2019: Fair Value Valuation Technique Unobservable Inputs/Assumptions Range (Weighted- Average) (In June 30, 2020 Recurring fair value measurements Privately issued mortgage- backed securities $ 16 Two independent pricing quotes — — Net other assets (liabilities) (a) 40,106 Discounted cash flow Commitment expirations 0%-100%(19%) December 31, 2019 Recurring fair value measurements Privately issued mortgage- backed securities $ 16 Two independent pricing quotes — — Net other assets (liabilities) (a) 10,740 Discounted cash flow Commitment expirations 0%-99% (13%) (a) Other Level 3 assets (liabilities) consist of commitments to originate real estate loans. Sensitivity of fair value measurements to changes in unobservable inputs An increase (decrease) in the estimate of expirations for commitments to originate real estate loans would generally result in a lower (higher) 11. Fair value measurements, continued Disclosures of fair value of financial instruments The carrying amounts and estimated fair value for financial instrument assets (liabilities) are presented in the following table: June 30, 2020 Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Cash and cash equivalents $ 1,354,815 1,354,815 1,307,683 47,132 — Interest-bearing deposits at banks 20,888,341 20,888,341 — 20,888,341 — Trading account assets 1,293,534 1,293,534 48,741 1,244,793 — Investment securities 8,454,344 8,561,449 67,888 8,417,724 75,837 Loans and leases: Commercial loans and leases 29,203,862 28,736,876 — — 28,736,876 Commercial real estate loans 37,159,451 35,781,888 — 255,442 35,526,446 Residential real estate loans 15,611,462 15,812,617 — 4,010,171 11,802,446 Consumer loans 15,782,773 15,207,433 — — 15,207,433 Allowance for credit losses (1,638,236 ) — — — — Loans and leases, net 96,119,312 95,538,814 — 4,265,613 91,273,201 Accrued interest receivable 380,859 380,859 — 380,859 — Financial liabilities: Noninterest-bearing deposits $ (45,397,843 ) (45,397,843 ) — (45,397,843 ) — Savings and interest-checking deposits (63,623,406 ) (63,623,406 ) — (63,623,406 ) — Time deposits (5,078,426 ) (5,118,204 ) — (5,118,204 ) — Deposits at Cayman Islands office (868,284 ) (868,284 ) — (868,284 ) — Short-term borrowings (52,298 ) (52,298 ) — (52,298 ) — Long-term borrowings (6,321,291 ) (6,366,011 ) — (6,366,011 ) — Accrued interest payable (104,301 ) (104,301 ) — (104,301 ) — Trading account liabilities (137,994 ) (137,994 ) — (137,994 ) — Other financial instruments: Commitments to originate real estate loans for sale $ 40,106 40,106 — — 40,106 Commitments to sell real estate loans (10,563 ) (10,563 ) — (10,563 ) — Other credit-related commitments (136,840 ) (136,840 ) — — (136,840 ) Interest rate swap agreements used for interest rate risk management (249 ) (249 ) — (249 ) — 11. Fair value measurements, continued December 31, 2019 Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Cash and cash equivalents $ 1,432,805 1,432,805 1,394,984 37,821 — Interest-bearing deposits at banks 7,190,154 7,190,154 — 7,190,154 — Federal funds sold 3,500 3,500 — 3,500 — Trading account assets 470,129 470,129 49,040 421,089 — Investment securities 9,497,251 9,539,540 100,637 9,351,793 87,110 Loans and leases: Commercial loans and leases 23,838,168 23,510,908 — — 23,510,908 Commercial real estate loans 35,541,914 35,517,180 — 28,338 35,488,842 Residential real estate loans 16,156,094 16,227,274 — 3,990,848 12,236,426 Consumer loans 15,386,693 15,413,262 — — 15,413,262 Allowance for credit losses (1,051,071 ) — — — — Loans and leases, net 89,871,798 90,668,624 — 4,019,186 86,649,438 Accrued interest receivable 333,142 333,142 — 333,142 — Financial liabilities: Noninterest-bearing deposits $ (32,396,407 ) (32,396,407 ) — (32,396,407 ) — Savings and interest-checking deposits (54,932,162 ) (54,932,162 ) — (54,932,162 ) — Time deposits (5,757,456 ) (5,829,347 ) — (5,829,347 ) — Deposits at Cayman Islands office (1,684,044 ) (1,684,044 ) — (1,684,044 ) — Short-term borrowings (62,363 ) (62,363 ) — (62,363 ) — Long-term borrowings (6,986,186 ) (7,063,165 ) — (7,063,165 ) — Accrued interest payable (105,374 ) (105,374 ) — (105,374 ) — Trading account liabilities (79,903 ) (79,903 ) — (79,903 ) — Other financial instruments: Commitments to originate real estate loans for sale $ 10,740 10,740 — — 10,740 Commitments to sell real estate loans 300 300 — 300 — Other credit-related commitments (136,470 ) (136,470 ) — — (136,470 ) Interest rate swap agreements used for interest rate risk management (1,762 ) (1,762 ) — (1,762 ) — With the exception of marketable securities, certain off-balance sheet financial instruments and mortgage loans originated for sale, the Company’s financial instruments are not readily marketable and market prices do not exist. The Company, in attempting to comply with the provisions of GAAP that require disclosures of fair value of financial instruments, has not attempted to market its financial instruments to potential buyers, if any exist. Since negotiated prices in illiquid markets depend greatly upon the then present motivations of the buyer and seller, it is reasonable to assume that actual sales prices could vary widely from any estimate of fair value made without the benefit of negotiations. Additionally, changes in market interest rates can dramatically impact the value of financial instruments in a short period of time. The Company does not believe that the estimated information presented herein is representative of the earnings power or value of the Company. The preceding analysis, which is inherently limited in depicting fair value, also does not consider any value associated with existing customer relationships nor the ability of the Company to create value through loan origination, deposit gathering or fee generating activities. Many of the estimates presented herein are based upon the use of highly subjective information and assumptions and, accordingly, the results may not be precise. Management believes that fair value estimates may not be comparable between financial institutions due to the wide range of permitted valuation techniques and numerous estimates which must be made. Furthermore,

Commitments and contingencies

Commitments and contingencies	6 Months Ended
	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and contingencies	12. Commitments and contingencies In the normal course of business, various commitments and contingent liabilities are outstanding. The following table presents the Company's significant commitments. Certain of these commitments are not included in the Company's consolidated balance sheet. June 30, December 31, 2020 2019 (In thousands) Commitments to extend credit Home equity lines of credit $ 5,556,034 $ 5,442,160 Commercial real estate loans to be sold 236,832 164,076 Other commercial real estate 8,640,169 9,029,608 Residential real estate loans to be sold 1,030,144 423,056 Other residential real estate 713,200 448,375 Commercial and other 18,256,994 16,170,731 Standby letters of credit 2,394,261 2,441,432 Commercial letters of credit 37,859 41,059 Financial guarantees and indemnification contracts 4,306,209 4,108,572 Commitments to sell real estate loans 1,478,551 906,037 Commitments to extend credit are agreements to lend to customers, generally having fixed expiration dates or other termination clauses that may require payment of a fee. In addition to the amounts in the preceding table, the Company had discretionary funding commitments to commercial customers of $10.0 billion and $9.1 billion at June 30, 2020 and December 31, 2019, respectively, that the Company had the unconditional right to cancel prior to funding. Standby and commercial letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. Standby letters of credit generally are contingent upon the failure of the customer to perform according to the terms of the underlying contract with the third party, whereas commercial letters of credit are issued to facilitate commerce and typically result in the commitment being funded when the underlying transaction is consummated between the customer and a third party. The credit risk associated with commitments to extend credit and standby and commercial letters of credit is essentially the same as that involved with extending loans to customers and is subject to normal credit policies. Collateral may be obtained based on management's assessment of the customer's creditworthiness. Financial guarantees and indemnification contracts are oftentimes similar to standby letters of credit and include mandatory purchase agreements issued to ensure that customer obligations are fulfilled, recourse obligations associated with sold loans, and other guarantees of customer performance or compliance with designated rules and regulations. Included in financial guarantees and indemnification contracts are loan principal amounts sold with recourse in conjunction with the Company's involvement in the Fannie Mae Delegated Underwriting and Servicing program. The Company's maximum credit risk for recourse associated with loans sold under this program totaled approximately $3.9 billion at each of June 30, 2020 and December 31, 2019. Since many loan commitments, standby letters of credit, and guarantees and indemnification contracts expire without being funded in whole or in part, the contract amounts are not necessarily indicative of future cash flows. The Company utilizes commitments to sell real estate loans to hedge exposure to changes in the fair value of real estate loans held for sale. Such commitments are considered derivatives and along with commitments to originate real estate loans to be held for sale are generally recorded in the consolidated balance sheet at estimated fair market value. The Company is contractually obligated to repurchase previously sold residential real estate loans that do not ultimately meet investor sale criteria related to underwriting procedures or loan documentation. When required to do so, the Company may reimburse loan purchasers for losses incurred or may repurchase certain loans. The Company reduces residential mortgage banking revenues by an estimate for losses related to its obligations to loan purchasers. 12. Commitments and contingencies, continued The amount of those charges is based on the volume of loans sold, the level of reimbursement requests received from loan purchasers and estimates of losses that may be associated with previously sold loans. At June 30, 2020, the Company believes that its obligation to loan purchasers was not material to the Company’s consolidated financial position. Wilmington Trust, N.A., a wholly owned subsidiary of M&T, provides retirement services, including serving in certain trustee roles relating to Employee Stock Ownership Plans (“ESOPs”). Beginning in 2010, the U.S. Department of Labor (“DOL”) announced that it would increase its focus on ESOP transactions, particularly with regard to valuation issues relating to ESOP transactions. Beginning in late 2013, Wilmington Trust, N.A. began receiving requests for information and subpoenas relating to certain ESOP transactions for which it acted as trustee. In June 2016, Wilmington Trust, N.A. received a DOL subpoena seeking information on its global ESOP trustee business. In addition to these investigations, the DOL commenced three lawsuits against Wilmington Trust, N.A. relating to its role as trustee of three ESOP transactions. In July 2019, Wilmington Trust, N.A. reached a settlement in principle with the DOL to resolve certain pending DOL ESOP matters. On April 28, 2020, Wilmington Trust N.A. and the DOL executed a formal settlement agreement. The total amount of the settlement was $88 million, which included $80 million in payments to 21 ESOPs. The settlement amount was within the Company’s reserve for litigation matters and substantially all was paid in the second quarter of 2020. Wilmington Trust, N.A. has also been named as a defendant in five private party lawsuits relating to its role as trustee for five ESOP transactions. Three of the five private party lawsuits relating to ESOP transactions have been resolved through settlements, two of which have been preliminarily approved by Courts, and are in the process of administration. The third settled ESOP private action was settled on an individual basis and, therefore, does not require Court approval. None of those three settlements are material. Under applicable transaction documents, Wilmington Trust, N.A. may be entitled to indemnification by the ESOP plan sponsors. These matters could result in damages, settlements, penalties, restitution, reputational damage or additional costs and expenses. M&T and its subsidiaries are subject in the normal course of business to various other pending and threatened legal proceedings and matters in which claims for monetary damages are asserted. On an on-going basis management, after consultation with legal counsel, assesses the Company’s liabilities and contingencies in connection with such proceedings. For those matters where it is probable that the Company will incur losses and the amounts of the losses can be reasonably estimated, the Company records an expense and corresponding liability in its consolidated financial statements. To the extent pending or threatened litigation could result in exposure in excess of the recorded liability, the amount of such excess is not currently estimable. Although not considered probable, the range of reasonably possible losses for such matters in the aggregate, beyond the existing recorded liability, was estimated to be between $0 and $25 million as of June 30, 2020. Although the Company does not believe that the outcome of pending legal matters will be material to the Company’s consolidated financial position, it cannot rule out the possibility that such outcomes will be material to the consolidated results of operations for a particular reporting period in the future.

Segment information

Segment information	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Segment information	13. Segment information Reportable segments have been determined based upon the Company's internal profitability reporting system, which is organized by strategic business unit. Certain strategic business units have been combined for segment information reporting purposes where the nature of the products and services, the type of customer and the distribution of those products and services are similar. The reportable segments are Business Banking, Commercial Banking, Commercial Real Estate, Discretionary Portfolio, Residential Mortgage Banking and Retail Banking. The financial information of the Company's segments was compiled utilizing the accounting policies described in note 22 of Notes to Financial Statements in the 2019 Annual Report. The management accounting policies and processes utilized in compiling segment financial information are highly subjective and, unlike financial accounting, are not based on authoritative guidance similar to GAAP. As a result, the financial information of the reported segments is not necessarily comparable with similar information reported by other financial institutions. 13. Segment information, continued Furthermore, changes in management structure or allocation methodologies and procedures may result in changes in reported segment financial data. Information about the Company's segments is presented in the following table: Three Months Ended June 30 2020 2019 Total Revenues(a) Inter- segment Revenues Net Income (Loss) Total Revenues(a) Inter- segment Revenues Net Income (Loss) (In thousands) Business Banking $ 138,086 144 37,563 $ 140,767 1,004 42,250 Commercial Banking 287,525 249 111,030 278,110 887 123,507 Commercial Real Estate 227,113 60 107,083 225,442 406 121,629 Discretionary Portfolio 138,827 (9,861 ) 95,691 60,976 (9,291 ) 38,040 Residential 142,045 21,016 37,400 96,449 17,150 7,642 Retail Banking 353,521 267 86,498 436,593 2,787 140,494 All Other 157,293 (11,875 ) (234,211 ) 315,239 (12,943 ) (302 ) Total $ 1,444,410 — 241,054 $ 1,553,576 — 473,260 Six Months Ended June 30 2020 2019 Total Revenues(a) Inter- segment Revenues Net Income (Loss) Total Revenues(a) Inter- segment Revenues Net Income (Loss) (In thousands) Business Banking $ 275,919 1,029 70,489 $ 280,089 1,860 85,521 Commercial Banking 579,301 1,302 254,762 545,600 1,727 255,725 Commercial Real Estate 450,418 469 224,491 444,615 760 239,127 Discretionary Portfolio 188,046 (22,898 ) 121,359 124,893 (18,590 ) 77,212 Residential Mortgage Banking 267,606 42,433 62,016 180,210 31,664 20,583 Retail Banking 756,204 534 196,744 867,484 5,298 285,560 All Other 433,081 (22,869 ) (419,985 ) 661,510 (22,719 ) (7,726 ) Total $ 2,950,575 — 509,876 $ 3,104,401 — 956,002 13. Segment information, continued Average Total Assets Six Months Ended June 30 Year Ended December 2020 2019 2019 (In millions) Business Banking $ 7,235 5,724 5,793 Commercial Banking 30,603 27,981 28,142 Commercial Real Estate 25,340 23,720 23,921 Discretionary Portfolio 26,821 29,888 29,081 Residential Mortgage Banking 3,113 2,173 2,611 Retail Banking 16,039 14,580 15,083 All Other 19,362 13,601 14,953 Total $ 128,513 117,667 119,584 (a) Total revenues are comprised of net interest income and other income. Net interest income is the difference between taxable-equivalent interest earned on assets and interest paid on liabilities owed by a segment and a funding charge (credit) based on the Company's internal funds transfer and allocation methodology. Segments are charged a cost to fund any assets (e.g. loans) and are paid a funding credit for any funds provided (e.g. deposits). The taxable-equivalent adjustment aggregated $4,234,000 and $5,925,000 for the three-month periods ended June 30, 2020 and 2019, respectively, and $9,297,000 and $11,892,000 for the six-month periods ended June 30, 2020 and 2019, respectively, and is eliminated in "All Other" total revenues. Intersegment revenues are included in total revenues of the reportable segments. The elimination of intersegment revenues is included in the determination of "All Other" total revenues

Relationship with Bayview Lendi

Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P.	6 Months Ended
	Jun. 30, 2020
Text Block [Abstract]
Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P.	14. Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P. M&T holds a minority interest in Bayview Lending Group LLC ("BLG"), a privately-held commercial mortgage company. That investment had no remaining carrying value Bayview Financial Holdings, L.P. (together with its affiliates, "Bayview Financial"), a privately-held specialty finance company, is BLG's majority investor. In addition to their common investment in BLG, the Company and Bayview Financial conduct other business activities with each other. The Company has obtained loan servicing rights for mortgage loans from BLG and Bayview Financial having outstanding principal balances of $2.1 billion and $2.2 billion at June 30, 2020 and December 31, 2019, respectively. Revenues from those servicing rights were $2 million and $3 million for the three-month periods ended June 30, 2020 and 2019, respectively, and $5 million and $6 million for the six-month periods ended June 30, 2020 and 2019, respectively. The Company sub-services residential mortgage loans for Bayview Financial having outstanding principal balances of $64.7 billion and $62.8 billion at June 30, 2020 and December 31, 2019, respectively. Revenues earned for sub-servicing loans for Bayview Financial were $34 million and $29 million for the three-month periods ended June 30, 2020 and 2019, respectively and $71 million and $57 million for the six-month periods ended June 30, 2020 and 2019, respectively. In addition, the Company held $86 million and $93 million of mortgage-backed securities in its held-to-maturity portfolio at June 30, 2020 and December 31, 2019, respectively, that were securitized by Bayview Financial. At June 30, 2020, the Company held $168 million of Bayview Financial’s $1.0 billion syndicated loan facility. Also, in the second quarter the Company extended two $100 million secured loan facilities to certain funds managed by Bayview Financial which had an outstanding balance of $199 million at June 30, 2020.

Recent accounting developments

Recent accounting developments	6 Months Ended
	Jun. 30, 2020
Accounting Changes And Error Corrections [Abstract]
Recent accounting developments	15. Recent accounting developments The following table provides a description of accounting standards that were adopted by the Company in 2020 as well as standards that are not effective that could have an impact to M&T’s consolidated financial statements upon adoption. Standard Description Required date of adoption Effect on consolidated financial statements Standards Adopted in 2020 Measurement of Credit Losses on Financial Instruments The amended guidance replaces the incurred loss model for determining the allowance for credit losses. The guidance requires financial assets measured at amortized cost to be presented at the net amount expected to be collected. The allowance for credit losses will represent a valuation account that is deducted from the amortized cost basis of the financial assets to present their net carrying value at the amount expected to be collected. The income statement will reflect the measurement of credit losses for newly recognized financial assets as well as expected increases or decreases of expected credit losses that have taken place during the period. When determining the allowance, expected credit losses over the contractual term of the financial asset(s) (taking into account prepayments) will be estimated considering relevant information about past events, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount. The amended guidance also requires recording an allowance for credit losses for purchased financial assets with a more-than-insignificant amount of credit deterioration since origination. The initial allowance for these assets will be added to the purchase price at acquisition rather than being reported as an expense. Subsequent changes in the allowance will be recorded in the income statement as an adjustment the to the provision for credit losses. In addition, the amended guidance requires credit losses relating to debt securities to be recorded through an allowance for credit losses. January 1, 2020 The Company adopted the guidance on January 1, 2020. The Company’s approach for estimating current expected credit losses for loans includes utilizing macro-economic assumptions to project losses over a two-year reasonable and supportable forecast period. Subsequent to the forecast period, the Company reverts to longer term historical loss experience to estimate expected credit losses over the remaining contractual life. Based on portfolio composition, then current economic conditions, and reasonable and supportable forecasts of future conditions, the Company recognized an increase to the allowance for credit losses of $132 million upon adoption of the standard as of January 1, 2020 as compared with the allowance for credit losses recognized on its consolidated balance sheet at December 31, 2019. The $132 million increase was recognized as a cumulative-effect adjustment to retained earnings as of January 1, 2020. The effect on the allowance for credit losses was primarily attributable to increases in reserves for residential mortgage loans and consumer loans, which generally have longer estimated lives as compared with commercial and commercial real estate loans. The adoption did not have a material effect on the allowance for credit losses for debt securities. Simplifying the Test for Goodwill Impairment The amended guidance eliminates step 2 from the goodwill impairment test. January 1, 2020 The Company adopted the amended guidance effective January 1, 2020 using a prospective transition method and will incorporate the guidance as necessary when circumstances arise for the guidance to be utilized. The Company does not expect the guidance will have a material impact on its consolidated financial statements, unless at some point in the future one of its reporting units were to fail step 1 of the goodwill impairment test. 15. Recent accounting developments, continued Standard Description Required date of adoption Effect on consolidated financial statements Standards Adopted in 2020 Changes to the Disclosure Requirements for Fair Value Measurements The amended guidance modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurements. The amendments are a result of the disclosure framework project that focuses on improvements to the effectiveness of disclosures in the notes to financial statements. The amendments remove, modify, and add certain disclosure requirements. The disclosure requirements removed relating to public companies are (1) the amount and reason for transfers between Level 1 and Level 2 of the fair value hierarchy, (2) the policy for timing of transfers between levels, and (3) the valuation process for Level 3 fair value measurements. The disclosure requirements modified relating to public companies are (1) for investments in certain entities that calculate net asset value, an entity is required to disclose the timing of liquidation of an investee’s asset and the date when restrictions from redemption might lapse only if the investee has communicated the timing to the entity or announced the timing publicly, and (2) the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as a result of the use of unobservable inputs. The disclosure requirements added relating to public companies are (1) to disclose the changes in unrealized gains and losses for the period for recurring Level 3 fair value measurements, and (2) to disclose the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. January 1, 2020 The Company adopted the amended guidance effective January 1, 2020. A prospective transition method is being used for the amendments relating to disclosures being added under the guidance. Such disclosures relate to changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty. All other amendments relating to removing or modifying certain disclosures are applied retrospectively. The adoption of the guidance did not have a material impact on the Company’s consolidated financial statements. Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract The amended guidance requires a hosting arrangement that is a service contract to follow the guidance in Subtopic 350-40 to determine which implementation costs to capitalize and which costs to expense. January 1, 2020 The Company adopted the amended guidance effective January 1, 2020 using a prospective transition method. The impact of the guidance on the Company’s consolidated financial statements is dependent on the nature and amount of actual expenditures, but is not expected to be material. Improvements to Related Party Guidance for VIEs The amended guidance requires that indirect interests held through related parties in common control arrangements should be considered on a proportional basis for determining whether fees paid to decision makers and service providers are variable interests. January 1, 2020 The guidance did not have a material impact on the Company’s consolidated financial statements. 15. Recent accounting developments, continued Standard Description Required date of adoption Effect on consolidated financial statements Standards Not Yet Adopted as of June 30, 2020 Changes to the Disclosure Requirements for Defined Benefit Plans The amended guidance modifies the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The disclosure requirements being removed relating to public companies are (1) the amounts in accumulated other comprehensive income expected to be recognized as components of net periodic benefit cost over the next fiscal year, (2) the amount and timing of plan assets expected to be returned to the employer, (3) the 2001 disclosure requirement relating to Japanese Welfare Pension Insurance Law, (4) related party disclosures about the amount of future annual benefits covered by insurance, and (5) the effects of a one-percentage-point change in assumed health care cost trends on the benefit cost and obligation. The disclosure requirements being added relating to public companies are (1) the weighted-average interest crediting rates for cash balance plans , and (2) an explanation of the reasons for significant gains and losses related to changes in the benefit obligation for the period. January 1, 2021 Early adoption permitted The amendments should be applied retrospectively. The Company does not expect the guidance to have a material impact on its consolidated financial statements. Clarifying the Interactions Between Equity Securities, Equity Method and Joint Ventures, and Derivatives and Hedging The amendments clarify the following guidance: 1. That an entity should consider observable transactions that require it to either apply or discontinue the equity method of accounting for the purposes of applying the measurement alternative in the equity securities investments guidance immediately before applying or upon discontinuing the equity method of accounting. 2. For the purpose of applying the derivatives and hedging guidance an entity should not consider whether, upon the settlement of a forward contract or exercise of a purchased option, individually or with existing investments, the underlying securities would be accounted for under the equity method of accounting or the fair value option in accordance with the financial instruments guidance. An entity also would evaluate the remaining characteristics in the derivatives and hedging guidance to determine the accounting for those forward contracts and purchased options. January 1, 2021 Early adoption permitted The amendments should be applied on a prospective basis. The Company does not expect the guidance will have a material impact on its consolidated financial statements. 15. Recent accounting developments, continued Standard Description Required date of adoption Effect on consolidated financial statements Standards Not Yet Adopted as of June 30, 2020 Simplifying the Accounting for Income Taxes The amendments remove the following exceptions for accounting for income taxes: 1. Exception to the incremental approach for intraperiod tax allocation when there is a loss from continuing operations and income or a gain from other items (for example, discontinued operations or other comprehensive income) 2. Exception to the requirement to recognize a deferred tax liability for equity method investments when a foreign subsidiary becomes an equity method investment 3. Exception to the ability not to recognize a deferred tax liability for a foreign subsidiary when a foreign equity method investment becomes a subsidiary 4. Exception to the general methodology for calculating income taxes in an interim period when a year-to-date loss exceeds the anticipated loss for the year. The amendments also simplify the accounting for income taxes by doing the following: 1. Requiring that an entity recognize a franchise tax (or similar tax) that is partially based on income as an income-based tax and account for any incremental amount incurred as a non-income-based tax. 2. Requiring that an entity evaluate when a step up in the tax basis of goodwill should be considered part of the business combination in which the book goodwill was originally recognized and when it should be considered a separate transaction. 3. Specifying that an entity is not required to allocate the consolidated amount of current and deferred tax expense to a legal entity that is not subject to tax in its separate financial statements. However, an entity may elect to do so (on an entity-by-entity basis) for a legal entity that is both not subject to tax and disregarded by the taxing authority. 4. Requiring that an entity reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. 5. Making minor Codification improvements for income taxes related to employee stock ownership plans and investments in qualified affordable housing projects accounted for using the equity method. January 1, 2021 Early adoption permitted The amendments related to separate financial statements of legal entities that are not subject to tax should be applied on a retrospective basis for all periods presented. The amendments related to changes in ownership of foreign equity method investments or foreign subsidiaries should be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. The amendments related to franchise taxes that are partially based on income should be applied on either a retrospective basis for all periods presented or a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. All other amendments should be applied on a prospective basis. Early adoption of the amendments in an interim period would require recognition of any adjustments as of the beginning of the annual period that includes that interim period. Additionally, an early adoption election would require adoption of all the amendments in the same period. The Company is evaluating the impact that the guidance will have on its consolidated financial statements. 15. Recent accounting developments, continued Standard Description Required date of adoption Effect on consolidated financial statements Standards Not Yet Adopted as of June 30, 2020 Reference Rate Reform The amendments provide optional expedients and exceptions for applying GAAP to contracts,hedging relationships, and other transactions affected by reference rate reform. The amendments apply only to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The amendments (1) apply to contract modifications that replace a reference rate affected by reference rate reform, (2) provide exceptions to existing guidance related to changes to the critical terms of a hedging relationship due to reference rate reform (3) provide optional expedients for fair value hedging relationships, cash flow hedging relationships, and net investment hedging relationships, and (4) provide a onetime election to sell, transfer, or both sell and transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform and that are classified as held to maturity before January 1, 2020. Beginning March 12, 2020 The amendments for contract modifications can be elected to be applied as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020. The amendments for existing hedging relationships can be elected to be applied as of the beginning of the interim period that includes March 12, 2020 and to new eligible hedging relationships entered into after the beginning of the interim period that includes March 12, 2020. The Company is evaluating the impact that the guidance will have on its consolidated financial statements.

Significant accounting polici_2

Significant accounting policies and current environment (Policies)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Basis of Accounting	The consolidated interim financial statements of M&T Bank Corporation (“M&T”) and subsidiaries (“the Company”) were compiled in accordance with generally accepted accounting principles (“GAAP”) using the accounting policies set forth in note 1 of Notes to Financial Statements included in Form 10-K for the year ended December 31, 2019 (“2019 Annual Report”), except that effective January 1, 2020 the Company adopted accounting guidance related to the recognition of expected credit losses that is discussed in notes 2, 3 and 15 herein. The financial statements contain all adjustments which are, in the opinion of management, necessary for a fair statement of the Company’s financial position, results of operations and cash flows for the interim periods presented.
Risk and Uncertainty	The United States has been operating under a state of emergency related to the Coronavirus Disease 2019 (“COVID-19”) pandemic since March 13, 2020.  The direct and indirect effects of the COVID-19 pandemic have resulted in a dramatic reduction in economic activity that has severely hampered the ability for businesses and consumers to meet their current repayment obligations. The effects of the pandemic contributed to a significant increase in the provision for credit losses during the first two quarters of 2020. The Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”), in addition to providing financial assistance to both businesses and consumers, creates a forbearance program for federally-backed mortgage loans, protects borrowers from negative credit  reporting due to loan  accommodations related to the national  emergency, and provides financial  institutions the option to temporarily suspend certain requirements under GAAP related to troubled debt restructurings for a limited period of time to account for the effects of COVID-19. The bank regulatory agencies have likewise issued guidance encouraging financial institutions to work prudently with borrowers who are, or may be, unable to meet their contractual payment obligations because of the effects of COVID-19. That guidance, with concurrence of the Financial Accounting Standards Board, and provisions of the CARES Act allow modifications made on a good faith basis in response to COVID-19 to borrowers who were generally current with their payments prior to any relief, to not be treated as troubled debt restructurings nor be reported as past due. Modifications may include payment deferrals, fee waivers, extensions of repayment term, or other delays in payment. The Company has been working with its customers affected by COVID-19 and has granted modifications across many of its loan portfolios. To the extent that such modifications meet the criteria previously described, the modified loans have not been classified as troubled debt restructurings nor reported as past due.

Investment securities (Tables)

Investment securities (Tables)	6 Months Ended
	Jun. 30, 2020
Investments Debt And Equity Securities [Abstract]
Amortized Cost and Estimated Fair Value of Investment Securities	The amortized cost and estimated fair value of investment securities were as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (In thousands) June 30, 2020 Investment securities available for sale: U.S. Treasury and federal agencies $ 9,653 $ 246 $ 6 $ 9,893 Obligations of states and political subdivisions 513 1 3 511 Mortgage-backed securities: Government issued or guaranteed 5,439,071 252,007 917 5,690,161 Privately issued 16 — — 16 Other debt securities 134,435 914 14,656 120,693 5,583,688 253,168 15,582 5,821,274 Investment securities held to maturity: U.S. Treasury and federal agencies 2,999 — — 2,999 Obligations of states and political subdivisions 2,220 13 — 2,233 Mortgage-backed securities: Government issued or guaranteed 2,064,946 117,092 41 2,181,997 Privately issued 85,780 9,410 19,369 75,821 Other debt securities 3,037 — — 3,037 2,158,982 126,515 19,410 2,266,087 Total debt securities $ 7,742,670 $ 379,683 $ 34,992 $ 8,087,361 Equity and other securities: Readily marketable equity — at fair value $ 72,907 $ 20,704 $ — $ 93,611 Other — at cost 380,477 — — 380,477 Total equity and other securities $ 453,384 $ 20,704 $ — $ 474,088 December 31, 2019 Investment securities available for sale: U.S. Treasury and federal agencies $ 9,742 $ 41 $ 16 $ 9,767 Obligations of states and political subdivisions 776 2 3 775 Mortgage-backed securities: Government issued or guaranteed 6,113,913 88,634 21,607 6,180,940 Privately issued 16 — — 16 Other debt securities 133,829 2,046 8,597 127,278 6,258,276 90,723 30,223 6,318,776 Investment securities held to maturity: U.S. Treasury and federal agencies 249,862 286 — 250,148 Obligations of states and political subdivisions 4,140 16 — 4,156 Mortgage-backed securities: Government issued or guaranteed 2,306,180 50,381 1,992 2,354,569 Privately issued 93,496 11,779 18,181 87,094 Other debt securities 3,239 — — 3,239 2,656,917 62,462 20,173 2,699,206 Total debt securities $ 8,915,193 $ 153,185 $ 50,396 $ 9,017,982 Equity and other securities: Readily marketable equity — at fair value $ 105,524 $ 34,786 $ 269 $ 140,041 Other — at cost 381,517 — — 381,517 Total equity and other securities $ 487,041 $ 34,786 $ 269 $ 521,558
Amortized Cost And Estimated Fair Value Of Debt Securities By Contractual Maturity Table Text Block	At June 30, 2020, the amortized cost and estimated fair value of debt securities by contractual maturity were as follows: Amortized Cost Estimated Fair Value (In thousands) Debt securities available for sale: Due in one year or less $ 6,067 6,089 Due after one year through five years 10,149 10,646 Due after five years through ten years 98,385 90,175 Due after ten years 30,000 24,187 144,601 131,097 Mortgage-backed securities available for sale 5,439,087 5,690,177 $ 5,583,688 5,821,274 Debt securities held to maturity: Due in one year or less $ 4,674 4,678 Due after one year through five years 545 554 Due after ten years 3,037 3,037 8,256 8,269 Mortgage-backed securities held to maturity 2,150,726 2,257,818 $ 2,158,982 2,266,087
Investment Securities in Continuous Unrealized Loss Position	A summary of investment securities that as of June 30, 2020 and December 31, 2019 had been in a continuous unrealized loss position for less than twelve months and those that had been in a continuous unrealized loss position for twelve months or longer follows: Less Than 12 Months 12 Months or More Fair Value Unrealized Losses Fair Value Unrealized Losses (In thousands) June 30, 2020 Investment securities available for sale: U.S. Treasury and federal agencies $ 985 (6 ) — — Obligations of states and political subdivisions — — 135 (3 ) Mortgage-backed securities: Government issued or guaranteed 23,855 (416 ) 25,930 (501 ) Other debt securities 54,951 (4,385 ) 54,318 (10,271 ) 79,791 (4,807 ) 80,383 (10,775 ) Investment securities held to maturity: Mortgage-backed securities: Government issued or guaranteed 8,430 (41 ) — — Privately issued 7,916 (22 ) 45,908 (19,347 ) 16,346 (63 ) 45,908 (19,347 ) Total $ 96,137 (4,870 ) 126,291 (30,122 ) December 31, 2019 Investment securities available for sale: U.S. Treasury and federal agencies $ 1,406 (7 ) 2,893 (9 ) Obligations of states and political subdivisions — — 277 (3 ) Mortgage-backed securities: Government issued or guaranteed 117,299 (222 ) 2,002,364 (21,385 ) Other debt securities 6,600 (354 ) 56,313 (8,243 ) 125,305 (583 ) 2,061,847 (29,640 ) Investment securities held to maturity: Mortgage-backed securities: Government issued or guaranteed 2,727 (5 ) 145,235 (1,987 ) Privately issued — — 49,656 (18,181 ) 2,727 (5 ) 194,891 (20,168 ) Total $ 128,032 (588 ) 2,256,738 (49,808 )

Loans and leases and the allo_2

Loans and leases and the allowance for credit losses (Tables)	6 Months Ended
	Jun. 30, 2020
Receivables [Abstract]
Summary of Current, Past Due and Nonaccrual Loans	A summary of current, past due and nonaccrual loans as of June 30, 2020 and December 31, 2019 follows: Current 30-89 Days Past Due Accruing Loans Due 90 Days or More Nonaccrual Total (In thousands) June 30, 2020 Commercial, financial, leasing, etc. $ 28,855,500 53,005 10,703 284,654 $ 29,203,862 Real estate: Commercial 27,250,342 148,129 17,305 172,488 27,588,264 Residential builder and developer 1,418,354 33,752 — 1,748 1,453,854 Other commercial construction 7,983,195 23,911 24,801 85,426 8,117,333 Residential 12,746,530 218,870 479,027 306,907 13,751,334 Residential — limited documentation 1,715,896 25,537 — 118,695 1,860,128 Consumer: Home equity lines and loans 4,107,387 34,341 — 77,094 4,218,822 Recreational finance 6,342,914 30,170 — 24,152 6,397,236 Automobile 3,680,749 41,375 — 42,736 3,764,860 Other 1,346,276 8,910 3,919 42,750 1,401,855 Total $ 95,447,143 618,000 535,755 1,156,650 $ 97,757,548 Current 30-89 Days Past Due Accruing Loans Due 90 Days or More (a) Accruing Loans Acquired a Discount Past Due 90 days or More (b) Purchased Impaired (c) Nonaccrual Total (In thousands) December 31, 2019 Commercial, financial, leasing, etc. $ 23,290,797 184,011 16,776 27 — 346,557 $ 23,838,168 Real estate: Commercial 26,311,414 165,579 6,740 — 15,601 158,474 26,657,808 Residential builder and developer 1,521,315 21,195 — — 753 3,982 1,547,245 Other commercial construction 7,204,148 95,346 3,360 — 1,237 32,770 7,336,861 Residential 12,760,040 451,274 486,515 5,788 143,145 235,663 14,082,425 Residential — limited documentation 1,858,037 65,215 181 — 66,809 83,427 2,073,669 Consumer: Home equity lines and loans 4,386,511 30,229 — 1,662 — 63,215 4,481,617 Recreational finance 5,484,997 36,827 — 99 — 14,219 5,536,142 Automobile 3,787,221 78,478 — — — 21,293 3,886,992 Other 1,395,240 45,978 5,156 32,056 — 3,512 1,481,942 Total $ 87,999,720 1,174,132 518,728 39,632 227,545 963,112 $ 90,922,869 (a) Excludes loans acquired at a discount. (b) Loans acquired at a discount that were recorded at fair value at acquisition date. This category does not include purchased impaired loans that are presented separately. (c) Accruing loans acquired at a discount that were impaired at acquisition date and recorded at fair value.
Summary of Outstanding Loan Balances Related To COVID-19 Modifications Granted	A summary of outstanding loan balances for which COVID-19 related modifications were granted as of June 30, 2020 is presented below. These loans meet the criteria described in note 1 and, as such, are not considered past due or otherwise in default of loan terms. Loans to motor vehicle and recreational finance dealers comprised $3.3 billion and $823 million of the total COVID-19 modifications of commercial, financial, leasing and commercial real estate loans, respectively. (In thousands) Commercial, financial, leasing, etc. $ 5,302,196 Real estate: Commercial 7,802,006 Residential builder and developer 18,253 Other commercial construction 861,536 Residential 1,737,483 Residential — limited documentation 538,671 Consumer: Home equity lines and loans 88,162 Recreational finance 254,205 Automobile 326,113 Other 16,611 Total $ 16,945,236
Outstanding Principal Balance and Carrying Amount of Loans and Included in Consolidated Balance Sheet	The outstanding principal balance and the carrying amount of loans acquired at a discount that were recorded at fair value at the acquisition date for which interest income was recognized based on expected future cash flows that were included in the consolidated balance sheet at December 31, 2019 were as follows: (In thousands) Outstanding principal balance $ 769,414 Carrying amount: Commercial, financial, leasing, etc. 21,114 Commercial real estate 94,890 Residential real estate 341,807 Consumer 77,785 $ 535,596
Summary of Changes in Accretable Yield for Acquired Loans	A summary of changes in the accretable yield for loans acquired at a discount for the three months and six months ended June 30, 2019 follows: Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Purchased Other Purchased Other Impaired Acquired Impaired Acquired (In thousands) Balance at beginning of period $ 140,317 $ 93,687 $ 147,210 $ 96,907 Interest income (9,632 ) (9,666 ) (27,714 ) (19,383 ) Reclassifications from nonaccretable balance 16,419 3,457 27,608 8,322 Other (a) — 3,433 — 5,065 Balance at end of period $ 147,104 $ 90,911 $ 147,104 $ 90,911 (a) Other changes in expected cash flows included changes in interest rates and prepayment assumptions.
Summary of Loan grades applied various classes of Commercial and Real Estate Loans	The following table summarizes the loan grades applied at June 30, 2020 to the various classes of the Compan Term Loans by Origination Year Revolving Revolving Loans Converted to Term 2020 2019 2018 2017 2016 Prior Loans Loans Total (In thousands) Commercial, financial, leasing, etc.: Loan grades: Pass $ 7,944,081 2,571,703 1,744,756 1,074,677 878,129 1,579,718 11,451,339 32,192 $ 27,276,595 Criticized accrual 313,697 88,164 164,361 64,980 50,254 82,987 868,964 9,206 1,642,613 Criticized nonaccrual 2,689 7,816 50,512 24,345 20,238 48,234 123,671 7,149 284,654 Total commercial, financial, leasing, etc. $ 8,260,467 2,667,683 1,959,629 1,164,002 948,621 1,710,939 12,443,974 48,547 $ 29,203,862 Real estate: Commercial: Loan grades: Pass $ 2,055,007 4,937,718 3,679,741 3,005,081 3,131,570 6,729,170 844,868 — $ 24,383,155 Criticized accrual 206,417 446,695 396,270 141,128 634,733 1,165,443 41,935 — 3,032,621 Criticized nonaccrual — 3,527 6,089 21,882 29,149 111,409 432 — 172,488 Total commercial real estate $ 2,261,424 5,387,940 4,082,100 3,168,091 3,795,452 8,006,022 887,235 — $ 27,588,264 Residential builder and developer: Loan grades: Pass $ 285,891 526,779 254,416 51,814 14,710 16,755 223,428 — $ 1,373,793 Criticized accrual 4,086 12,964 16,349 17,164 302 22,557 4,891 — 78,313 Criticized nonaccrual — — — — 302 1,446 — — 1,748 Total residential builder and developer $ 289,977 539,743 270,765 68,978 15,314 40,758 228,319 — $ 1,453,854 Other commercial construction: Loan grades: Pass $ 459,366 2,340,490 2,314,047 1,254,678 404,993 318,387 80,428 — $ 7,172,389 Criticized accrual 22,850 205,065 264,298 216,998 138,268 12,039 — — 859,518 Criticized nonaccrual — — — 350 57,773 22,171 5,132 — 85,426 Total other commercial construction $ 482,216 2,545,555 2,578,345 1,472,026 601,034 352,597 85,560 — $ 8,117,333
Summary of loans in Accrual and Nonaccrual Status	. A summary of loans in accrual and nonaccrual status at June 30, 2020 for the various classes of the Company’s residential real estate loans and consumer loans by origination year is as follows. Term Loans by Origination Year Revolving Revolving Loans Converted to Term 2020 2019 2018 2017 2016 Prior Loans Loans Total (In thousands) Residential: Current $ 1,386,049 1,446,544 627,380 711,769 735,767 7,785,981 53,040 — $ 12,746,530 30-89 days past due 2,291 7,259 6,718 20,267 4,256 177,700 379 — 218,870 Accruing loans past due 90 days or more 117 8,995 26,337 118,899 25,353 299,326 — — 479,027 Nonaccrual 29 4,223 2,930 5,696 950 292,859 220 — 306,907 Total residential $ 1,388,486 1,467,021 663,365 856,631 766,326 8,555,866 53,639 — $ 13,751,334 Residential - limited documentation: Current $ — — — — — 1,715,896 — — $ 1,715,896 30-89 days past due — — — — — 25,537 — — 25,537 Accruing loans past due 90 days or more — — — — — — — — — Nonaccrual — — — — — 118,695 — — 118,695 Total residential - limited documentation $ — — — — — 1,860,128 — — $ 1,860,128 Consumer: Home equity lines and loans: Current $ 852 4,931 2,550 2,731 155 60,569 2,687,506 1,348,093 $ 4,107,387 30-89 days past due — 20 — — — 1,770 — 32,551 34,341 Accruing loans past due 90 days or more — — — — — — — — — Nonaccrual — — — — — 5,895 1,196 70,003 77,094 Total home equity lines and loans $ 852 4,951 2,550 2,731 155 68,234 2,688,702 1,450,647 $ 4,218,822 3. Loans and leases and the allowance for credit losses, continued Term Loans by Origination Year Revolving Revolving Loans Converted to Term 2020 2019 2018 2017 2016 Prior Loans Loans Total (In thousands) Recreational finance: Current $ 1,453,572 2,021,651 1,055,732 728,343 410,077 673,539 — — $ 6,342,914 30-89 days past due 2,415 7,557 5,208 5,096 2,815 7,079 — — 30,170 Accruing loans past due 90 days or more — — — — — — — — — Nonaccrual 783 3,479 4,229 4,844 2,666 8,151 — — 24,152 Total recreational finance $ 1,456,770 2,032,687 1,065,169 738,283 415,558 688,769 — — $ 6,397,236 Automobile: Current $ 567,784 1,341,719 802,096 595,776 253,239 120,135 — — $ 3,680,749 30-89 days past due 1,495 9,879 10,557 10,642 5,590 3,212 — — 41,375 Accruing loans past due 90 days or more — — — — — — — — — Nonaccrual 1,125 7,176 10,987 11,054 7,058 5,336 — — 42,736 Total automobile $ 570,404 1,358,774 823,640 617,472 265,887 128,683 — — $ 3,764,860 Other: Current $ 93,225 174,085 73,089 47,297 8,532 32,837 915,187 2,024 $ 1,346,276 30-89 days past due 1,246 778 557 311 56 389 5,016 557 8,910 Accruing loans past due 90 days or more — — — — — 291 3,628 — 3,919 Nonaccrual 5,722 544 551 214 52 253 35,103 311 42,750 Total other $ 100,193 175,407 74,197 47,822 8,640 33,770 958,934 2,892 $ 1,401,855 Total loans and leases at June 30, 2020 $ 14,810,789 16,179,761 11,519,760 8,136,036 6,816,987 21,445,766 17,346,363 1,502,086 $ 97,757,548
Summary of Loan Grades	The following table summarizes the loan grades applied at December 31, 2019 to the various classes of the Company’s commercial loans and commercial real estate loans. Real Estate Commercial, Residential Other Financial, Builder and Commercial Leasing, etc. Commercial Developer Construction (In thousands) December 31, 2019 Pass $ 22,595,821 25,728,725 1,419,162 7,092,799 Criticized accrual 895,790 770,609 124,101 211,292 Criticized nonaccrual 346,557 158,474 3,982 32,770 Total $ 23,838,168 26,657,808 1,547,245 7,336,861
Changes in Allowance for Credit Losses	Changes in the allowance for credit losses for the three months ended June 30, 2020 were as follows: Commercial, Financial, Real Estate Leasing, etc. Commercial Residential Consumer Unallocated Total (In thousands) Beginning balance $ 358,092 433,689 115,792 476,793 — $ 1,384,366 Provision for credit losses 69,400 159,090 2,850 93,660 — 325,000 Net charge-offs Charge-offs (32,608 ) (17,472 ) (1,609 ) (39,708 ) — (91,397 ) Recoveries 3,373 1,014 1,888 13,992 — 20,267 Net (charge-offs) recoveries (29,235 ) (16,458 ) 279 (25,716 ) — (71,130 ) Ending balance $ 398,257 576,321 118,921 544,737 — $ 1,638,236 Changes in the allowance for credit losses for the three months ended June 30, 2019 were as follows: Commercial, Financial, Real Estate Leasing, etc. Commercial Residential Consumer Unallocated Total (In thousands) Beginning balance $ 335,620 337,995 65,136 203,045 77,541 $ 1,019,337 Provision for credit losses 10,337 14,501 (2,376 ) 31,594 944 55,000 Net charge-offs Charge-offs (16,608 ) (10,165 ) (3,263 ) (39,370 ) — (69,406 ) Recoveries 6,506 965 1,514 15,951 — 24,936 Net charge-offs (10,102 ) (9,200 ) (1,749 ) (23,419 ) — (44,470 ) Ending balance $ 335,855 343,296 61,011 211,220 78,485 $ 1,029,867
Loan and Leases Considered Nonaccrual and Interest Income Recognized on Loans	3. Loans and leases and the allowance for credit losses, continued Information with respect to loans and leases that were considered nonaccrual at the beginning and end of the reporting period and the interest income recognized on such loans for the three-month and six-month periods ended June 30, 2020 and 2019 follows. June 30, 2020 March 31, 2020 January 1, 2020 Three Months Ended June 30, 2020 Six Months Ended June 30, 2020 Amortized Cost with Allowance Amortized Cost Total Amortized Cost Amortized Cost Interest Income Recognized Interest Income Recognized (In thousands) Commercial, financial, leasing, etc. $ 138,556 146,098 284,654 286,647 346,743 1,298 3,036 Real estate: Commercial 57,675 114,813 172,488 188,469 173,796 4,697 5,789 Residential builder and developer 1,748 — 1,748 3,204 4,708 11 59 Other commercial construction 42,969 42,457 85,426 34,935 35,881 5,716 6,577 Residential 80,772 226,135 306,907 293,638 322,504 5,029 11,848 Residential — limited documentation 26,460 92,235 118,695 119,317 114,667 256 457 Consumer: Home equity lines and loans 38,890 38,204 77,094 63,071 65,039 760 2,219 Recreational finance 16,264 7,888 24,152 13,405 14,308 154 306 Automobile 35,510 7,226 42,736 19,251 21,293 45 92 Other 7,747 35,003 42,750 39,811 35,394 161 315 Total $ 446,591 710,059 1,156,650 1,061,748 1,134,333 18,127 30,698 3. Loans and leases and the allowance for credit losses, continued June 30, 2019 March 31, 2019 January 1, 2019 Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Amortized Cost with Allowance Amortized Cost Total Amortized Cost Amortized Cost Interest Income Recognized Interest Income Recognized (In thousands) Commercial, financial, leasing, etc. $ 150,974 72,759 223,733 245,819 234,423 3,635 6,716 Real estate: Commercial 52,443 150,673 203,116 207,709 203,672 2,314 3,410 Residential builder and developer 1,429 4,556 5,985 4,392 4,798 35 219 Other commercial construction 25,572 7,197 32,769 19,899 22,205 544 1,181 Residential 57,323 153,599 210,922 210,266 233,352 2,990 6,589 Residential — limited documentation 25,796 61,755 87,551 84,863 84,685 274 526 Consumer: Home equity lines and loans 25,530 41,397 66,927 69,245 71,292 1,461 2,771 Recreational finance 6,493 4,660 11,153 10,972 11,199 142 284 Automobile 13,852 6,318 20,170 21,209 23,359 53 107 Other 2,757 301 3,058 7,237 4,623 125 247 Total $ 362,169 503,215 865,384 881,611 893,608 11,573 22,050
Loan Modification Activities that were Considered Troubled Debt Restructurings	The table that follows summarizes the Company’s loan modification activities that were considered troubled debt restructurings for the three-month and six-month periods ended June 30, 2020 and 2019: Post-modification (a) Number Pre- modification Recorded Investment Principal Deferral Interest Rate Reduction Other Combination of Concession Types Total Three Months Ended June 30, 2020 (Dollars in thousands) Commercial, financial, leasing, etc. 135 $ 55,136 $ 17,551 $ — $ 31,605 $ 5,514 $ 54,670 Real estate: Commercial 46 41,872 10,511 333 4,800 16,348 31,992 Residential builder and developer 1 91 — — — 90 90 Residential 25 8,872 3,101 — — 6,533 9,634 Residential — limited documentation — — — — — — — Consumer: Home equity lines and loans 120 7,571 147 — — 7,437 7,584 Recreational finance 271 10,795 10,795 — — — 10,795 Automobile 1,461 26,352 26,352 — — — 26,352 Other 335 2,183 682 — — 1,501 2,183 Total 2,394 $ 152,872 $ 69,139 $ 333 $ 36,405 $ 37,423 $ 143,300 Three Months Ended June 30, 2019 Commercial, financial, leasing, etc. 24 $ 2,597 $ 667 $ — $ — $ 1,891 $ 2,558 Real estate: Commercial 14 10,340 2,577 — — 7,641 10,218 Other commercial construction 1 1,038 — — 1,033 1,033 Residential 26 7,513 4,008 — — 4,034 8,042 Residential — limited documentation 2 612 160 — — 465 625 Consumer: Home equity lines and loans 13 1,273 53 — — 1,225 1,278 Recreational finance 1 15 15 — — — 15 Automobile 12 189 189 — — — 189 Total 93 $ 23,577 $ 7,669 $ — $ — $ 16,289 $ 23,958 3. Loans and leases and the allowance for credit losses, continued Post-modification (a) Number Pre- modification Recorded Investment Principal Deferral Interest Rate Reduction Other Combination of Concession Types Total Six Months Ended June 30, 2020 (Dollars in thousands) Commercial, financial, leasing, etc. 167 $ 67,828 $ 22,617 $ — $ 31,605 $ 12,501 $ 66,723 Real estate: Commercial 56 81,514 11,866 333 4,800 52,316 69,315 Residential builder and developer 1 91 — — — 90 90 Residential 52 19,050 6,348 — — 15,510 21,858 Residential — limited documentation 9 2,980 2,667 — — 1,232 3,899 Consumer: Home equity lines and loans 126 8,309 559 — — 7,771 8,330 Recreational finance 274 10,885 10,885 — — — 10,885 Automobile 1,470 26,534 26,534 — — — 26,534 Other 335 2,183 682 — — 1,501 2,183 Total 2,490 $ 219,374 $ 82,158 $ 333 $ 36,405 $ 90,921 $ 209,817 Six Months Ended June 30, 2019 Commercial, financial, leasing, etc. 89 $ 33,212 $ 7,141 $ — $ — $ 26,161 $ 33,302 Real estate: Commercial 29 19,581 3,564 — — 15,608 19,172 Residential builder and developer 2 1,330 1,068 — — — 1,068 Other commercial construction 2 1,456 — — 1,399 1,399 Residential 43 11,329 5,759 — — 6,307 12,066 Residential — limited documentation 3 848 399 — — 465 864 Consumer: Home equity lines and loans 20 1,749 90 — — 1,679 1,769 Recreational finance 5 103 103 — — — 103 Automobile 32 506 469 — — 37 506 Total 225 $ 70,114 $ 18,593 $ — $ — $ 51,656 $ 70,249 (a) Financial effects impacting the recorded investment included principal payments or advances, charge-offs and capitalized escrow arrearages. The present value of interest rate concessions, discounted at the effective rate of the original loan, was not material.

Revenue from contracts with c_2

Revenue from contracts with customers (Tables)	6 Months Ended
	Jun. 30, 2020
ASU 2014-09 [Member]
Summary of Sources of Noninterest Income that are Subject to Noted Accounting Guidance	The following tables summarize sources of the Company’s noninterest income during the three-month and six-month periods ended June 30, 2020 and 2019 that are subject to the noted accounting guidance. Business Banking Commercial Banking Commercial Real Estate Discretionary Portfolio Residential Mortgage Banking Retail Banking All Other Total Three Months Ended June 30, 2020 (In thousands) Classification in consolidated statement of income Service charges on deposit accounts $ 11,271 22,514 2,565 — — 40,024 1,081 $ 77,455 Trust income 6 137 — — — — 151,739 151,882 Brokerage services income — — — — — — 10,463 10,463 Other revenues from operations: Merchant discount and credit card fees 8,159 8,891 379 — — 3,450 176 21,055 Other — 787 1,188 150 1,052 3,166 9,421 15,764 $ 19,436 32,329 4,132 150 1,052 46,640 172,880 $ 276,619 Three Months Ended June 30, 2019 Classification in consolidated statement of income Service charges on deposit accounts $ 15,175 23,094 2,362 — 2 65,661 1,493 $ 107,787 Trust income 7 224 — — — — 144,151 144,382 Brokerage services income — — — — — — 12,478 12,478 Other revenues from operations: Merchant discount and credit card fees 9,895 13,129 496 — — 4,566 602 28,688 Other — 3,145 2,680 641 1,033 9,329 8,595 25,423 $ 25,077 39,592 5,538 641 1,035 79,556 167,319 $ 318,758 5. Revenue from contracts with customers, continued Business Banking Commercial Banking Commercial Real Estate Discretionary Portfolio Residential Mortgage Banking Retail Banking All Other Total Six Months Ended June 30, 2020 (In thousands) Classification in consolidated statement of income Service charges on deposit accounts $ 26,521 46,671 5,377 — — 101,694 3,353 $ 183,616 Trust income 18 441 — — — — 300,174 300,633 Brokerage services income — — — — — — 23,592 23,592 Other revenues from operations: Merchant discount and credit card fees 18,490 22,207 1,228 — — 5,721 576 48,222 Other — 2,973 2,031 1,007 1,974 9,148 21,937 39,070 $ 45,029 72,292 8,636 1,007 1,974 116,563 349,632 $ 595,133 Six Months Ended June 30, 2019 Classification in consolidated statement of income Service charges on deposit accounts $ 30,284 46,304 4,888 — 4 126,812 2,607 $ 210,899 Trust income 12 438 — — — — 276,718 277,168 Brokerage services income — — — — — — 24,954 24,954 Other revenues from operations: Merchant discount and credit card fees 18,777 25,221 1,102 — — 7,704 1,022 53,826 Other — 4,147 4,468 1,042 2,097 17,823 19,083 48,660 $ 49,073 76,110 10,458 1,042 2,101 152,339 324,384 $ 615,507

Pension plans and other postr_2

Pension plans and other postretirement benefits (Tables)	6 Months Ended
	Jun. 30, 2020
Compensation And Retirement Disclosure [Abstract]
Net Periodic Defined Benefit Cost for Defined Benefit Plans	Net periodic defined benefit cost for defined benefit plans consisted of the following: Pension Benefits Other Postretirement Benefits Three Months Ended June 30 2020 2019 2020 2019 (In thousands) Service cost $ 5,258 4,559 262 229 Interest cost on projected benefit obligation 17,824 20,590 451 569 Expected return on plan assets (31,281 ) (30,470 ) — — Amortization of prior service cost (credit) 154 154 (1,194 ) (1,190 ) Amortization of net actuarial loss (gain) 15,098 6,546 (318 ) (323 ) Net periodic cost (benefit) $ 7,053 1,379 (799 ) (715 ) Pension Benefits Other Postretirement Benefits Six Months Ended June 30 2020 2019 2020 2019 (In thousands) Service cost $ 9,972 8,646 485 429 Interest cost on projected benefit obligation 35,710 40,790 870 1,172 Expected return on plan assets (62,756 ) (61,070 ) — — Amortization of prior service cost (credit) 279 279 (2,369 ) (2,365 ) Amortization of net actuarial loss (gain) 29,048 10,996 (618 ) (623 ) Net periodic cost (benefit) $ 12,253 (359 ) (1,632 ) (1,387 )

Earnings per common share (Tabl

Earnings per common share (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Computations of Basic Earnings Per Common Share	The computations of basic earnings per common share follow: Three Months Ended June 30 Six Months Ended June 30 2020 2019 2020 2019 (In thousands, except per share) Income available to common shareholders: Net income $ 241,054 473,260 509,876 956,002 Less: Preferred stock dividends (17,050 ) (18,130 ) (34,128 ) (36,260 ) Net income available to common equity 224,004 455,130 475,748 919,742 Less: Income attributable to unvested stock-based compensation awards (906 ) (2,498 ) (1,954 ) (5,024 ) Net income available to common shareholders $ 223,098 452,632 473,794 914,718 Weighted-average shares outstanding: Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards 129,059 136,182 129,750 137,403 Less: Unvested stock-based compensation awards (784 ) (749 ) (764 ) (749 ) Weighted-average shares outstanding 128,275 135,433 128,986 136,654 Basic earnings per common share $ 1.74 3.34 3.67 6.69
Computations of Diluted Earnings Per Common Share	The computations of diluted earnings per common share follow: Three Months Ended June 30 Six Months Ended June 30 2020 2019 2020 2019 (In thousands, except per share) Net income available to common equity $ 224,004 455,130 475,748 919,742 Less: Income attributable to unvested stock-based compensation awards (905 ) (2,497 ) (1,953 ) (5,023 ) Net income available to common shareholders $ 223,099 452,633 473,795 914,719 Adjusted weighted-average shares outstanding: Common and unvested stock-based compensation awards 129,059 136,182 129,750 137,403 Less: Unvested stock-based compensation awards (784 ) (749 ) (764 ) (749 ) Plus: Incremental shares from assumed conversion of stock-based compensation awards and warrants to purchase common stock 58 31 58 31 Adjusted weighted-average shares outstanding 128,333 135,464 129,044 136,685 Diluted earnings per common share $ 1.74 3.34 3.67 6.69

Comprehensive income (Tables)

Comprehensive income (Tables)	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Components of Other Comprehensive Income (Loss) and Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) to Net Income	The following tables display the components of other comprehensive income (loss) and amounts reclassified from accumulated other comprehensive income (loss) to net income: Investment Defined Benefit Total Amount Income Securities Plans Other Before Tax Tax Net (In thousands) Balance — January 1, 2020 $ 50,701 (464,548 ) 133,888 $ (279,959 ) 73,279 $ (206,680 ) Other comprehensive income before reclassifications: Unrealized holding gains, net 177,086 — — 177,086 (45,856 ) 131,230 Foreign currency translation adjustment — — (3,624 ) (3,624 ) 630 (2,994 ) Unrealized gains on cash flow hedges — — 511,195 511,195 (132,404 ) 378,791 Total other comprehensive income before reclassifications 177,086 — 507,571 684,657 (177,630 ) 507,027 Amounts reclassified from accumulated other comprehensive income that (increase) decrease net income: Amortization of unrealized holding losses on held-to-maturity (“HTM”) securities 1,619 — — 1,619 (a) (450 ) 1,169 Accretion of net gain on terminated cash flow hedges — — (64 ) (64 ) (c) 18 (46 ) Net yield adjustment from cash flow hedges currently in effect — — (101,194 ) (101,194 ) (a) 26,210 (74,984 ) Amortization of prior service credit — (2,090 ) — (2,090 ) (d) 650 (1,440 ) Amortization of actuarial losses — 28,430 — 28,430 (d) (8,846 ) 19,584 Total other comprehensive income 178,705 26,340 406,313 611,358 (160,048 ) 451,310 Balance — June 30, 2020 $ 229,406 (438,208 ) 540,201 $ 331,399 (86,769 ) $ 244,630 Balance — January 1, 2019 $ (200,107 ) (354,502 ) (14,719 ) $ (569,328 ) 149,247 $ (420,081 ) Other comprehensive income before reclassifications: Unrealized holding gains, net 207,802 — — 207,802 (54,609 ) 153,193 Foreign currency translation adjustment — — (507 ) (507 ) 107 (400 ) Unrealized gains on cash flow hedges — — 188,272 188,272 (49,497 ) 138,775 Total other comprehensive income before reclassifications 207,802 — 187,765 395,567 (103,999 ) 291,568 Amounts reclassified from accumulated other comprehensive income that (increase) decrease net income: Amortization of unrealized holding losses on HTM securities 1,691 — — 1,691 (a) (445 ) 1,246 Losses realized in net income 7 — — 7 (b) (2 ) 5 Accretion of net gain on terminated cash flow hedges — — (56 ) (56 ) (c) 14 (42 ) Net yield adjustment from cash flow hedges currently in effect — — 11,176 11,176 (a) (2,938 ) 8,238 Amortization of prior service credit — (2,086 ) — (2,086 ) (d) 548 (1,538 ) Amortization of actuarial losses — 10,373 — 10,373 (d) (2,727 ) 7,646 Total other comprehensive income 209,500 8,287 198,885 416,672 (109,549 ) 307,123 Balance — June 30, 2019 $ 9,393 (346,215 ) 184,166 $ (152,656 ) 39,698 $ (112,958 ) (a) Included in interest income. (b) Included in gain (loss) on bank investment securities. (c) Included in interest expense. (d) Included in other costs of operations. 8. Comprehensive income, continued
Accumulated Other Comprehensive Income (Loss), Net	Accumulated other comprehensive income (loss), net consisted of the following: Defined Cash Flow Investment Benefit Hedges Securities Plans and Total (In thousands) Balance — December 31, 2019 $ 37,380 (342,419 ) 98,359 $ (206,680 ) Net gain during period 132,399 18,144 300,767 451,310 Balance — June 30, 2020 $ 169,779 (324,275 ) 399,126 $ 244,630

Derivative financial instrume_2

Derivative financial instruments (Tables)	6 Months Ended
	Jun. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Information about Interest Rate Swap Agreements	Information about interest rate swap agreements entered into for interest rate risk management purposes summarized by type of financial instrument the swap agreements were intended to hedge follows: Weighted- Estimated Notional Average Average Rate Fair Value Amount Maturity Fixed Variable Gain (In thousands) (In (In June 30, 2020 Fair value hedges: Fixed rate long-term borrowings (b) $ 3,050,000 2.2 2.61 % .72 % $ (469 ) Cash flow hedges: Interest payments on variable rate commercial real estate loans (b)(c) 54,250,000 1.3 2.55 % .18 % 220 Total $ 57,300,000 1.3 $ (249 ) December 31, 2019 Fair value hedges: Fixed rate long-term borrowings (b) $ 3,800,000 2.2 2.51 % 2.27 % $ (567 ) Cash flow hedges: Interest payments on variable rate commercial real estate loans (b)(d) 53,750,000 1.4 2.44 % 1.73 % (1,195 ) Total $ 57,550,000 1.5 $ (1,762 ) (a) Certain clearinghouse exchanges consider payments by counterparties for variation margin on derivative instruments to be settlements of those positions. The impact of such treatment at June 30, 2020 and December 31, 2019 was a reduction of the estimated fair value gains on interest rate swap agreements designated as fair value hedges of $133.8 million and $45.1 million, respectively, and on interest rate swap agreements designated as cash flow hedges of $549.3 million and $140.7 million, respectively. (b) Under the terms of these agreements, the Company receives settlement amounts at a fixed rate and pays at a variable rate. (c) (d) .
Information about Fair Values of Derivative Instruments in Consolidated Balance Sheet	Information about the fair values of derivative instruments in the Company’s consolidated balance sheet and consolidated statement of income follows: Asset Derivatives Liability Derivatives Fair Value Fair Value June 30, December 31, June 30, December 31, 2020 2019 2020 2019 (In thousands) Derivatives designated and qualifying as hedging instruments Interest rate swap agreements (a) $ 818 $ 232 $ 1,067 $ 1,994 Commitments to sell real estate loans (a) 2,473 1,195 7,763 421 3,291 1,427 8,830 2,415 Derivatives not designated and qualifying as hedging instruments Mortgage-related commitments to originate real estate loans for sale (a) 40,727 11,965 621 1,225 Commitments to sell real estate loans (a) 2,253 3,074 7,526 3,548 Trading: Interest rate contracts (b) 1,231,484 398,295 127,008 68,103 Foreign exchange and other option and futures contracts (b) 12,925 12,506 10,986 11,800 1,287,389 425,840 146,141 84,676 Total derivatives $ 1,290,680 $ 427,267 $ 154,971 $ 87,091 (a) Asset derivatives are reported in other assets and liability derivatives are reported in other liabilities. (b) Asset derivatives are reported in trading account assets and liability derivatives are reported in other liabilities. The impact of variation margin payments at June 30, 2020 and December 31, 2019 was a reduction of the estimated fair value of interest rate contracts in the trading account in an asset position of $3.1 million and $43.3 million, respectively, and in a liability position of $1.0 billion and $281.3 million, respectively. Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount of the Hedged Item June 30, 2020 December 31, 2019 June 30, 2020 December 31, 2019 (In thousands) Location in the of the Hedged Items in Fair Value Long-term debt $ 3,180,022 $ 3,840,775 $ 132,069 $ 43,640
Information about Fair Values of Derivative Instruments in Consolidated Statement of Income	Amount of Gain (Loss) Recognized Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Derivative Hedged Item Derivative Hedged Item (In thousands) Derivatives in fair value hedging relationships Interest rate swap agreements: Fixed rate long-term borrowings (a) $ 117 (605 ) $ 56,679 (56,458 ) Derivatives not designated as hedging instruments Trading: Interest rate contracts (b) $ 978 $ 8,493 Foreign exchange and other option and futures contracts (b) 717 2,479 Total $ 1,695 $ 10,972 9. Derivative financial instruments, continued Amount of Gain (Loss) Recognized Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Derivative Hedged Item Derivative Hedged Item (In thousands) Derivatives in fair value hedging relationships Interest rate swap agreements: Fixed rate long-term borrowings (a) $ 88,827 (88,429 ) $ 90,859 (90,472 ) Derivatives not designated as hedging instruments Trading: Interest rate contracts (b) $ 13,764 $ 11,204 Foreign exchange and other option and futures contracts (b) 5,069 4,092 Total $ 18,833 $ 15,296 (a) Reported as an adjustment to interest expense. (b) Reported as trading account and foreign exchange gains.

Fair value measurements (Tables

Fair value measurements (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Estimated Fair Value on Recurring Basis	The following tables present assets and liabilities at June 30, 2020 and December 31, 2019 measured at estimated fair value on a recurring basis: Fair Value Measurements Level 1 Level 2 Level 3 (In thousands) June 30, 2020 Trading account assets $ 1,293,534 $ 48,741 $ 1,244,793 $ — Investment securities available for sale: U.S. Treasury and federal agencies 9,893 — 9,893 — Obligations of states and political subdivisions 511 — 511 — Mortgage-backed securities: Government issued or guaranteed 5,690,161 — 5,690,161 — Privately issued 16 — — 16 Other debt securities 120,693 — 120,693 — 5,821,274 — 5,821,258 16 Equity securities 93,611 67,888 25,723 — Real estate loans held for sale 695,969 — 695,969 — Other assets (a) 46,271 — 5,544 40,727 Total assets $ 7,950,659 $ 116,629 $ 7,793,287 $ 40,743 Trading account liabilities $ 137,994 $ — $ 137,994 $ — Other liabilities (a) 16,977 — 16,356 621 Total liabilities $ 154,971 $ — $ 154,350 $ 621 December 31, 2019 Trading account assets $ 470,129 $ 49,040 $ 421,089 $ — Investment securities available for sale: U.S. Treasury and federal agencies 9,767 — 9,767 — Obligations of states and political subdivisions 775 — 775 — Mortgage-backed securities: Government issued or guaranteed 6,180,940 — 6,180,940 — Privately issued 16 — — 16 Other debt securities 127,278 — 127,278 — 6,318,776 — 6,318,760 16 Equity securities 140,041 100,637 39,404 — Real estate loans held for sale 442,079 — 442,079 — Other assets (a) 16,466 — 4,501 11,965 Total assets $ 7,387,491 $ 149,677 $ 7,225,833 $ 11,981 Trading account liabilities $ 79,903 $ — $ 79,903 $ — Other liabilities (a) 7,188 — 5,963 1,225 Total liabilities $ 87,091 $ — $ 85,866 $ 1,225 (a) Comprised predominantly of interest rate swap agreements used for interest rate risk management (Level 2), commitments to sell real estate loans (Level 2) and commitments to originate real estate loans to be held for sale (Level 3).
Changes in Level 3 Assets and Liabilities Measured at Estimated Fair Value on Recurring Basis	The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the three months ended June 30, 2020 and 2019 were as follows: Investment Securities Available for Sale Privately Issued Mortgage-Backed Other Assets 2020 (In thousands) Balance — March 31, 2020 $ 16 35,027 Total gains realized/unrealized: Included in earnings — 48,732 (a) Settlements — — Transfers out of Level 3 — (43,653 ) (b) Balance — June 30, 2020 $ 16 40,106 Changes in unrealized gains included in earnings related to assets still held at June 30, 2020 $ — 33,725 (a) 2019 Balance — March 31, 2019 $ 16 7,433 Total gains realized/unrealized: Included in earnings — 36,463 (a) Settlements — — Transfers out of Level 3 — (26,696 ) (b) Balance — June 30, 2019 $ 16 17,200 Changes in unrealized gains included in earnings related to assets still held at June 30, 2019 $ — 17,464 (a) 11. Fair value measurements, continued The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis during the six months ended June 30, 2020 and 2019 were as follows: Investment Securities Available for Sale Privately Issued Mortgage-Backed Other Assets 2020 (In thousands) Balance — January 1, 2020 $ 16 10,740 Total gains realized/unrealized: Included in earnings — 92,813 (a) Settlements — — Transfers out of Level 3 — (63,447 ) (b) Balance — June 30, 2020 $ 16 40,106 Changes in unrealized gains included in earnings related to assets still held at June 30, 2020 $ — 38,514 (a) 2019 Balance — January 1, 2019 $ 22 7,712 Total gains realized/unrealized: Included in earnings — 53,009 (a) Settlements (6 ) — Transfers out of Level 3 — (43,521 ) (b) Balance — June 30, 2019 $ 16 17,200 Changes in unrealized gains included in earnings related to assets still held at June 30, 2019 $ — 17,372 (a) (a) Reported as mortgage banking revenues in the consolidated statement of income and includes the fair value of commitment issuances and expirations. (b) Transfers out of Level 3 consist of interest rate locks transferred to closed loans.
Quantitative Information Related to Significant Unobservable Inputs	The following tables present quantitative information about significant unobservable inputs used in the fair value measurements for certain Level 3 assets and liabilities at June 30, 2020 and December 31, 2019: Fair Value Valuation Technique Unobservable Inputs/Assumptions Range (Weighted- Average) (In June 30, 2020 Recurring fair value measurements Privately issued mortgage- backed securities $ 16 Two independent pricing quotes — — Net other assets (liabilities) (a) 40,106 Discounted cash flow Commitment expirations 0%-100%(19%) December 31, 2019 Recurring fair value measurements Privately issued mortgage- backed securities $ 16 Two independent pricing quotes — — Net other assets (liabilities) (a) 10,740 Discounted cash flow Commitment expirations 0%-99% (13%) (a) Other Level 3 assets (liabilities) consist of commitments to originate real estate loans. Sensitivity of fair value measurements to changes in unobservable inputs An increase (decrease) in the estimate of expirations for commitments to originate real estate loans would generally result in a lower (higher)
Carrying Amounts and Estimated Fair Value for Financial Instrument Assets (Liabilities)	The carrying amounts and estimated fair value for financial instrument assets (liabilities) are presented in the following table: June 30, 2020 Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Cash and cash equivalents $ 1,354,815 1,354,815 1,307,683 47,132 — Interest-bearing deposits at banks 20,888,341 20,888,341 — 20,888,341 — Trading account assets 1,293,534 1,293,534 48,741 1,244,793 — Investment securities 8,454,344 8,561,449 67,888 8,417,724 75,837 Loans and leases: Commercial loans and leases 29,203,862 28,736,876 — — 28,736,876 Commercial real estate loans 37,159,451 35,781,888 — 255,442 35,526,446 Residential real estate loans 15,611,462 15,812,617 — 4,010,171 11,802,446 Consumer loans 15,782,773 15,207,433 — — 15,207,433 Allowance for credit losses (1,638,236 ) — — — — Loans and leases, net 96,119,312 95,538,814 — 4,265,613 91,273,201 Accrued interest receivable 380,859 380,859 — 380,859 — Financial liabilities: Noninterest-bearing deposits $ (45,397,843 ) (45,397,843 ) — (45,397,843 ) — Savings and interest-checking deposits (63,623,406 ) (63,623,406 ) — (63,623,406 ) — Time deposits (5,078,426 ) (5,118,204 ) — (5,118,204 ) — Deposits at Cayman Islands office (868,284 ) (868,284 ) — (868,284 ) — Short-term borrowings (52,298 ) (52,298 ) — (52,298 ) — Long-term borrowings (6,321,291 ) (6,366,011 ) — (6,366,011 ) — Accrued interest payable (104,301 ) (104,301 ) — (104,301 ) — Trading account liabilities (137,994 ) (137,994 ) — (137,994 ) — Other financial instruments: Commitments to originate real estate loans for sale $ 40,106 40,106 — — 40,106 Commitments to sell real estate loans (10,563 ) (10,563 ) — (10,563 ) — Other credit-related commitments (136,840 ) (136,840 ) — — (136,840 ) Interest rate swap agreements used for interest rate risk management (249 ) (249 ) — (249 ) — December 31, 2019 Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Cash and cash equivalents $ 1,432,805 1,432,805 1,394,984 37,821 — Interest-bearing deposits at banks 7,190,154 7,190,154 — 7,190,154 — Federal funds sold 3,500 3,500 — 3,500 — Trading account assets 470,129 470,129 49,040 421,089 — Investment securities 9,497,251 9,539,540 100,637 9,351,793 87,110 Loans and leases: Commercial loans and leases 23,838,168 23,510,908 — — 23,510,908 Commercial real estate loans 35,541,914 35,517,180 — 28,338 35,488,842 Residential real estate loans 16,156,094 16,227,274 — 3,990,848 12,236,426 Consumer loans 15,386,693 15,413,262 — — 15,413,262 Allowance for credit losses (1,051,071 ) — — — — Loans and leases, net 89,871,798 90,668,624 — 4,019,186 86,649,438 Accrued interest receivable 333,142 333,142 — 333,142 — Financial liabilities: Noninterest-bearing deposits $ (32,396,407 ) (32,396,407 ) — (32,396,407 ) — Savings and interest-checking deposits (54,932,162 ) (54,932,162 ) — (54,932,162 ) — Time deposits (5,757,456 ) (5,829,347 ) — (5,829,347 ) — Deposits at Cayman Islands office (1,684,044 ) (1,684,044 ) — (1,684,044 ) — Short-term borrowings (62,363 ) (62,363 ) — (62,363 ) — Long-term borrowings (6,986,186 ) (7,063,165 ) — (7,063,165 ) — Accrued interest payable (105,374 ) (105,374 ) — (105,374 ) — Trading account liabilities (79,903 ) (79,903 ) — (79,903 ) — Other financial instruments: Commitments to originate real estate loans for sale $ 10,740 10,740 — — 10,740 Commitments to sell real estate loans 300 300 — 300 — Other credit-related commitments (136,470 ) (136,470 ) — — (136,470 ) Interest rate swap agreements used for interest rate risk management (1,762 ) (1,762 ) — (1,762 ) —

Commitments and contingencies (

Commitments and contingencies (Tables)	6 Months Ended
	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities Outstanding	The following table presents the Company's significant commitments. Certain of these commitments are not included in the Company's consolidated balance sheet. June 30, December 31, 2020 2019 (In thousands) Commitments to extend credit Home equity lines of credit $ 5,556,034 $ 5,442,160 Commercial real estate loans to be sold 236,832 164,076 Other commercial real estate 8,640,169 9,029,608 Residential real estate loans to be sold 1,030,144 423,056 Other residential real estate 713,200 448,375 Commercial and other 18,256,994 16,170,731 Standby letters of credit 2,394,261 2,441,432 Commercial letters of credit 37,859 41,059 Financial guarantees and indemnification contracts 4,306,209 4,108,572 Commitments to sell real estate loans 1,478,551 906,037

Segment information (Tables)

Segment information (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Information about Company's Segments	Information about the Company's segments is presented in the following table: Three Months Ended June 30 2020 2019 Total Revenues(a) Inter- segment Revenues Net Income (Loss) Total Revenues(a) Inter- segment Revenues Net Income (Loss) (In thousands) Business Banking $ 138,086 144 37,563 $ 140,767 1,004 42,250 Commercial Banking 287,525 249 111,030 278,110 887 123,507 Commercial Real Estate 227,113 60 107,083 225,442 406 121,629 Discretionary Portfolio 138,827 (9,861 ) 95,691 60,976 (9,291 ) 38,040 Residential 142,045 21,016 37,400 96,449 17,150 7,642 Retail Banking 353,521 267 86,498 436,593 2,787 140,494 All Other 157,293 (11,875 ) (234,211 ) 315,239 (12,943 ) (302 ) Total $ 1,444,410 — 241,054 $ 1,553,576 — 473,260 Six Months Ended June 30 2020 2019 Total Revenues(a) Inter- segment Revenues Net Income (Loss) Total Revenues(a) Inter- segment Revenues Net Income (Loss) (In thousands) Business Banking $ 275,919 1,029 70,489 $ 280,089 1,860 85,521 Commercial Banking 579,301 1,302 254,762 545,600 1,727 255,725 Commercial Real Estate 450,418 469 224,491 444,615 760 239,127 Discretionary Portfolio 188,046 (22,898 ) 121,359 124,893 (18,590 ) 77,212 Residential Mortgage Banking 267,606 42,433 62,016 180,210 31,664 20,583 Retail Banking 756,204 534 196,744 867,484 5,298 285,560 All Other 433,081 (22,869 ) (419,985 ) 661,510 (22,719 ) (7,726 ) Total $ 2,950,575 — 509,876 $ 3,104,401 — 956,002 13. Segment information, continued Average Total Assets Six Months Ended June 30 Year Ended December 2020 2019 2019 (In millions) Business Banking $ 7,235 5,724 5,793 Commercial Banking 30,603 27,981 28,142 Commercial Real Estate 25,340 23,720 23,921 Discretionary Portfolio 26,821 29,888 29,081 Residential Mortgage Banking 3,113 2,173 2,611 Retail Banking 16,039 14,580 15,083 All Other 19,362 13,601 14,953 Total $ 128,513 117,667 119,584 (a) Total revenues are comprised of net interest income and other income. Net interest income is the difference between taxable-equivalent interest earned on assets and interest paid on liabilities owed by a segment and a funding charge (credit) based on the Company's internal funds transfer and allocation methodology. Segments are charged a cost to fund any assets (e.g. loans) and are paid a funding credit for any funds provided (e.g. deposits). The taxable-equivalent adjustment aggregated $4,234,000 and $5,925,000 for the three-month periods ended June 30, 2020 and 2019, respectively, and $9,297,000 and $11,892,000 for the six-month periods ended June 30, 2020 and 2019, respectively, and is eliminated in "All Other" total revenues. Intersegment revenues are included in total revenues of the reportable segments. The elimination of intersegment revenues is included in the determination of "All Other" total revenues

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Estimated Fair Value of Investment Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Schedule Of Amortized Cost And Estimated Fair Value Of Investment Securities [Line Items]
Investment securities available for sale, amortized cost	$ 5,583,688	$ 6,258,276
Investment securities available for sale, gross unrealized gains	253,168	90,723
Investment securities available for sale, gross unrealized losses	15,582	30,223
Investment securities available for sale, estimated fair value	5,821,274	6,318,776
Amortized cost for held to maturity	2,158,982	2,656,917
Gross unrealized gains for held to maturity	126,515	62,462
Gross unrealized losses for held to maturity	19,410	20,173
Estimated fair value for held to maturity	2,266,087	2,699,206
Equity and other securities, Amortized Cost	453,384	487,041
Equity securities, Gross Unrealized Gains	20,704	34,786
Equity securities, Gross Unrealized Losses		269
Equity and other securities, Estimated Fair Value	474,088	521,558
Other securities, Amortized cost	380,477	381,517
Other securities, Estimated fair value	380,477	381,517
Total debt securities Amortized cost	7,742,670	8,915,193
Total debt securities Gross unrealized gains	379,683	153,185
Total debt securities Gross unrealized losses	34,992	50,396
Total debt securities Estimated fair value	8,087,361	9,017,982
Readily marketable securities Amortized cost	72,907	105,524
Readily marketable securities Gross unrealized gains	20,704	34,786
Readily marketable securities Gross unrealized losses		269
Readily marketable securities Estimated fair value	93,611	140,041
U.S. Treasury and Federal Agencies [Member]
Schedule Of Amortized Cost And Estimated Fair Value Of Investment Securities [Line Items]
Investment securities available for sale, amortized cost	9,653	9,742
Investment securities available for sale, gross unrealized gains	246	41
Investment securities available for sale, gross unrealized losses	6	16
Investment securities available for sale, estimated fair value	9,893	9,767
Amortized cost for held to maturity	2,999	249,862
Gross unrealized gains for held to maturity		286
Estimated fair value for held to maturity	2,999	250,148
Obligations of States and Political Subdivisions [Member]
Schedule Of Amortized Cost And Estimated Fair Value Of Investment Securities [Line Items]
Investment securities available for sale, amortized cost	513	776
Investment securities available for sale, gross unrealized gains	1	2
Investment securities available for sale, gross unrealized losses	3	3
Investment securities available for sale, estimated fair value	511	775
Amortized cost for held to maturity	2,220	4,140
Gross unrealized gains for held to maturity	13	16
Estimated fair value for held to maturity	2,233	4,156
Government Issued or Guaranteed [Member]
Schedule Of Amortized Cost And Estimated Fair Value Of Investment Securities [Line Items]
Investment securities available for sale, amortized cost	5,439,071	6,113,913
Investment securities available for sale, gross unrealized gains	252,007	88,634
Investment securities available for sale, gross unrealized losses	917	21,607
Investment securities available for sale, estimated fair value	5,690,161	6,180,940
Amortized cost for held to maturity	2,064,946	2,306,180
Gross unrealized gains for held to maturity	117,092	50,381
Gross unrealized losses for held to maturity	41	1,992
Estimated fair value for held to maturity	2,181,997	2,354,569
Privately Issued [Member]
Schedule Of Amortized Cost And Estimated Fair Value Of Investment Securities [Line Items]
Investment securities available for sale, amortized cost	16	16
Investment securities available for sale, estimated fair value	16	16
Amortized cost for held to maturity	85,780	93,496
Gross unrealized gains for held to maturity	9,410	11,779
Gross unrealized losses for held to maturity	19,369	18,181
Estimated fair value for held to maturity	75,821	87,094
Other Debt Securities [Member]
Schedule Of Amortized Cost And Estimated Fair Value Of Investment Securities [Line Items]
Investment securities available for sale, amortized cost	134,435	133,829
Investment securities available for sale, gross unrealized gains	914	2,046
Investment securities available for sale, gross unrealized losses	14,656	8,597
Investment securities available for sale, estimated fair value	120,693	127,278
Amortized cost for held to maturity	3,037	3,239
Estimated fair value for held to maturity	$ 3,037	$ 3,239

Investment Securities - Additio

Investment Securities - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)Security	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)Security	Jun. 30, 2019USD ($)
Amortized Cost And Fair Value Debt Securities [Abstract]
Gross realized gains(loss) on sale of investment securities	$ 0	$ 0	$ 0	$ 0
Gains (losses) on equity securities	$ 6,969,000	$ 8,911,000	$ (13,813,000)	$ 20,752,000
Number of debt securities with aggregate gross unrealized losses | Security	341		341
Unrealized losses on individual debt securities			$ (35,000,000)
Cost method equity securities	$ 380,000,000		$ 380,000,000

Investment Securities - Amort_2

Investment Securities - Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt securities available for sale:
Due in one year or less	$ 6,067
Due after one year through five years	10,149
Due after five years through ten years	98,385
Due after ten years	30,000
Total available for sale (amortized cost)	144,601
Mortgage-backed securities available for sale	5,439,087
Investment securities available for sale, amortized cost	5,583,688	$ 6,258,276
Debt securities held to maturity:
Due in one year or less	4,674
Due after one year through five years	545
Due after ten years	3,037
Total available for held to maturity (amortized cost)	8,256
Mortgage-backed securities held to maturity	2,150,726
Amortized cost for held to maturity	2,158,982	2,656,917
Debt securities available for sale:
Due in one year or less	6,089
Due after one year through five years	10,646
Due after five years through ten years	90,175
Due after ten years	24,187
Total available for sale (fair value)	131,097
Mortgage-backed securities available for sale	5,690,177
Total	5,821,274	6,318,776
Debt securities held to maturity:
Due in one year or less	4,678
Due after one year through five years	554
Due after ten years	3,037
Total available for held to maturity (fair value)	8,269
Mortgage-backed securities held to maturity	2,257,818
Total	$ 2,266,087	$ 2,699,206

Investment Securities - Investm

Investment Securities - Investment Securities in Continuous Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	$ 79,791	$ 125,305
Available For Sale Securities Continuous Unrealized Losses Position Less Than Twelve Months Aggregate Losses	(4,807)	(583)
Estimated fair value, 12 months or more	80,383	2,061,847
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(10,775)	(29,640)
Held to maturity, Estimated fair value, Less than 12 months	16,346	2,727
Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses	(63)	(5)
Held to maturity, Estimated fair value, 12 months or more	45,908	194,891
Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses	(19,347)	(20,168)
Total investment securities, fair value less than 12 months	96,137	128,032
Investment Securities Continuous Unrealized Loss Position Less Than Twelve Months Aggregate Losses	(4,870)	(588)
Total of investment securities, fair value, 12 Months or More	126,291	2,256,738
Investment Securities Continuous Unrealized Loss Position Twelve Months or Longer Aggregate Losses	(30,122)	(49,808)
U.S. Treasury and Federal Agencies [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	985	1,406
Available For Sale Securities Continuous Unrealized Losses Position Less Than Twelve Months Aggregate Losses	(6)	(7)
Estimated fair value, 12 months or more		2,893
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses		(9)
Obligations of States and Political Subdivisions [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, 12 months or more	135	277
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(3)	(3)
Government Issued or Guaranteed [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	23,855	117,299
Available For Sale Securities Continuous Unrealized Losses Position Less Than Twelve Months Aggregate Losses	(416)	(222)
Estimated fair value, 12 months or more	25,930	2,002,364
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(501)	(21,385)
Held to maturity, Estimated fair value, Less than 12 months	8,430	2,727
Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses	(41)	(5)
Held to maturity, Estimated fair value, 12 months or more		145,235
Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses		(1,987)
Other Debt Securities [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Estimated fair value, Less than 12 months	54,951	6,600
Available For Sale Securities Continuous Unrealized Losses Position Less Than Twelve Months Aggregate Losses	(4,385)	(354)
Estimated fair value, 12 months or more	54,318	56,313
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or More Aggregate Losses	(10,271)	(8,243)
Privately Issued [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Held to maturity, Estimated fair value, Less than 12 months	7,916
Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses	(22)
Held to maturity, Estimated fair value, 12 months or more	45,908	49,656
Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses	$ (19,347)	$ (18,181)

Loans and Leases and the Allo_3

Loans and Leases and the Allowance for Credit Losses - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	6 Months Ended	12 Months Ended
	Jan. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Loans And Leases Receivable [Line Items]
Increase in allowance for credit loss	$ 132
Effect of change in allowance for credit loss to non accrual loan	$ 171
Contractual principal and interest payments			$ 228
Amount of foreclosed residential real estate property held		$ 59	76
Loans secured by residential real estate that were in the process of foreclosure		$ 273	$ 402
Percentage loans in the process of foreclosure, serviced by other entities, classified as government guaranteed		40.00%
Maximum [Member]
Loans And Leases Receivable [Line Items]
Purchased impaired loans as a percentage of total assets			1.00%
Loan delinquent period		150 days
Minimum [Member]
Loans And Leases Receivable [Line Items]
Loan delinquent period		90 days
Minimum [Member] | Commercial Loans and Commercial Real Estate [Member]
Loans And Leases Receivable [Line Items]
Amount of real estate loan as reported as accruing or nonaccruing		$ 1
COVID-19 [Member]
Loans And Leases Receivable [Line Items]
Increases in criticized loans		3,700
Loans to Motor Vehicle [Member] | COVID-19 [Member]
Loans And Leases Receivable [Line Items]
Mortgage loans held for sale		3,300
Commercial Real Estate Loans [Member] | COVID-19 [Member]
Loans And Leases Receivable [Line Items]
Recreational finance dealers		823
Residential Mortgage Loans [Member] | One-to-Four Family Residential [Member]
Loans And Leases Receivable [Line Items]
Mortgage loans held for sale		440	$ 414
Commercial Real Estate Loans [Member] | One-to-Four Family Residential [Member]
Loans And Leases Receivable [Line Items]
Mortgage loans held for sale		255	$ 28
Commercial and Industrial Loans [Member] | COVID-19 [Member]
Loans And Leases Receivable [Line Items]
Increases in criticized loans		759
Commercial Real Estate | COVID-19 [Member]
Loans And Leases Receivable [Line Items]
Increases in criticized loans		2,300
Other Commercial Construction [Member] | COVID-19 [Member]
Loans And Leases Receivable [Line Items]
Increases in criticized loans		$ 668

Loans and Leases and the Allo_4

Loans and Leases and the Allowance for Credit Losses - Summary of Current, Past Due and Nonaccrual Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	$ 95,447,143	$ 87,999,720
30-89 Days Past Due	618,000	1,174,132
Accruing Loans Past Due 90 Days or More	535,755	518,728
Nonaccrual	1,156,650	963,112
Loans and leases, net of unearned discount	97,757,548	90,922,869
Purchased Impaired		227,545
Accruing Loans Acquired at Discount [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Loans Past Due 90 Days or More		39,632
Commercial, Financial, Leasing, etc. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	28,855,500	23,290,797
30-89 Days Past Due	53,005	184,011
Accruing Loans Past Due 90 Days or More	10,703	16,776
Nonaccrual	284,654	346,557
Loans and leases, net of unearned discount	29,203,862	23,838,168
Commercial, Financial, Leasing, etc. [Member] | Accruing Loans Acquired at Discount [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Loans Past Due 90 Days or More		27
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	27,250,342	26,311,414
30-89 Days Past Due	148,129	165,579
Accruing Loans Past Due 90 Days or More	17,305	6,740
Nonaccrual	172,488	158,474
Loans and leases, net of unearned discount	27,588,264	26,657,808
Purchased Impaired		15,601
Residential Builder and Developer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	1,418,354	1,521,315
30-89 Days Past Due	33,752	21,195
Nonaccrual	1,748	3,982
Loans and leases, net of unearned discount	1,453,854	1,547,245
Purchased Impaired		753
Other Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	7,983,195	7,204,148
30-89 Days Past Due	23,911	95,346
Accruing Loans Past Due 90 Days or More	24,801	3,360
Nonaccrual	85,426	32,770
Loans and leases, net of unearned discount	8,117,333	7,336,861
Purchased Impaired		1,237
Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	12,746,530	12,760,040
30-89 Days Past Due	218,870	451,274
Accruing Loans Past Due 90 Days or More	479,027	486,515
Nonaccrual	306,907	235,663
Loans and leases, net of unearned discount	13,751,334	14,082,425
Purchased Impaired		143,145
Residential [Member] | Accruing Loans Acquired at Discount [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Loans Past Due 90 Days or More		5,788
Residential Limited Documentation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	1,715,896	1,858,037
30-89 Days Past Due	25,537	65,215
Accruing Loans Past Due 90 Days or More		181
Nonaccrual	118,695	83,427
Loans and leases, net of unearned discount	1,860,128	2,073,669
Purchased Impaired		66,809
Home Equity Lines and Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	4,107,387	4,386,511
30-89 Days Past Due	34,341	30,229
Nonaccrual	77,094	63,215
Loans and leases, net of unearned discount	4,218,822	4,481,617
Home Equity Lines and Loans [Member] | Accruing Loans Acquired at Discount [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Loans Past Due 90 Days or More		1,662
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	6,342,914	5,484,997
30-89 Days Past Due	30,170	36,827
Nonaccrual	24,152	14,219
Loans and leases, net of unearned discount	6,397,236	5,536,142
Commercial Real Estate Loans [Member] | Accruing Loans Acquired at Discount [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Loans Past Due 90 Days or More		99
Loans to Motor Vehicle [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	3,680,749	3,787,221
30-89 Days Past Due	41,375	78,478
Nonaccrual	42,736	21,293
Loans and leases, net of unearned discount	3,764,860	3,886,992
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	1,346,276	1,395,240
30-89 Days Past Due	8,910	45,978
Accruing Loans Past Due 90 Days or More	3,919	5,156
Nonaccrual	42,750	3,512
Loans and leases, net of unearned discount	$ 1,401,855	1,481,942
Other [Member] | Accruing Loans Acquired at Discount [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing Loans Past Due 90 Days or More		$ 32,056

Loans and Leases and the Allo_5

Loans and Leases and the Allowance for Credit Losses - Summary of Outstanding Loan Balances Related to COVID-19 Modifications Granted (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	$ 97,757,548	$ 90,922,869
COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	16,945,236
Commercial, Financial, Leasing, etc. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	29,203,862	23,838,168
Commercial, Financial, Leasing, etc. [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	5,302,196
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	27,588,264	26,657,808
Commercial [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	7,802,006
Residential Builder and Developer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	1,453,854	1,547,245
Residential Builder and Developer [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	18,253
Other Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	8,117,333	7,336,861
Other Commercial Construction [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	861,536
Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	13,751,334	14,082,425
Residential [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	1,737,483
Residential Limited Documentation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	1,860,128	2,073,669
Residential Limited Documentation [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	538,671
Home Equity Lines and Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	4,218,822	4,481,617
Home Equity Lines and Loans [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	88,162
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	6,397,236	5,536,142
Commercial Real Estate Loans [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	254,205
Loans to Motor Vehicle [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	3,764,860	3,886,992
Loans to Motor Vehicle [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	326,113
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	1,401,855	$ 1,481,942
Other [Member] | COVID-19 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, net of unearned discount	$ 16,611

Loans and Leases and the Allo_6

Loans and Leases and the Allowance for Credit Losses - Outstanding Principal Balance and Carrying Amount of Loans and Included in Consolidated Balance Sheet (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Outstanding principal and carrying value of acquired loans recorded at fair value
Outstanding principal balance	$ 769,414
Carrying amount	535,596
Commercial, Financial, Leasing, etc. [Member]
Outstanding principal and carrying value of acquired loans recorded at fair value
Carrying amount	21,114
Commercial Real Estate [Member]
Outstanding principal and carrying value of acquired loans recorded at fair value
Carrying amount	94,890
One-to-Four Family Residential [Member]
Outstanding principal and carrying value of acquired loans recorded at fair value
Carrying amount	341,807
Consumer [Member]
Outstanding principal and carrying value of acquired loans recorded at fair value
Carrying amount	$ 77,785

Loans and Leases and the Allo_7

Loans and Leases and the Allowance for Credit Losses - Summary of Changes in Accretable Yield for Acquired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Purchased Impaired [Member]
Summary of changes in Accretable Yield for acquired loans
Balance at beginning of period	$ 140,317	$ 147,210
Interest income	(9,632)	(27,714)
Reclassifications from nonaccretable balance	16,419	27,608
Balance at end of period	147,104	147,104
Other Acquired [Member]
Summary of changes in Accretable Yield for acquired loans
Balance at beginning of period	93,687	96,907
Interest income	(9,666)	(19,383)
Reclassifications from nonaccretable balance	3,457	8,322
Other	3,433	5,065
Balance at end of period	$ 90,911	$ 90,911

Loans and Leases and the Allo_8

Loans and Leases and the Allowance for Credit Losses - Summary of Loan grades applied various classes of Commercial and Real Estate Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	$ 97,757,548	$ 90,922,869
Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	17,346,363
Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,502,086
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	29,203,862	23,838,168
Commercial, Financial, Leasing, etc. [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	27,276,595	22,595,821
Commercial, Financial, Leasing, etc. [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,642,613	895,790
Commercial, Financial, Leasing, etc. [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	284,654	346,557
Commercial, Financial, Leasing, etc. [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	12,443,974
Commercial, Financial, Leasing, etc. [Member] | Revolving Loans [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	11,451,339
Commercial, Financial, Leasing, etc. [Member] | Revolving Loans [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	868,964
Commercial, Financial, Leasing, etc. [Member] | Revolving Loans [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	123,671
Commercial, Financial, Leasing, etc. [Member] | Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	48,547
Commercial, Financial, Leasing, etc. [Member] | Revolving Loans Converted to Term Loans [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	32,192
Commercial, Financial, Leasing, etc. [Member] | Revolving Loans Converted to Term Loans [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	9,206
Commercial, Financial, Leasing, etc. [Member] | Revolving Loans Converted to Term Loans [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	7,149
Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	27,588,264	26,657,808
Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	24,383,155	25,728,725
Commercial [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	3,032,621	770,609
Commercial [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	172,488	158,474
Commercial [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	887,235
Commercial [Member] | Revolving Loans [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	844,868
Commercial [Member] | Revolving Loans [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	41,935
Commercial [Member] | Revolving Loans [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	432
Residential Builder and Developer [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,453,854	1,547,245
Residential Builder and Developer [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,373,793	1,419,162
Residential Builder and Developer [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	78,313	124,101
Residential Builder and Developer [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,748	3,982
Residential Builder and Developer [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	228,319
Residential Builder and Developer [Member] | Revolving Loans [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	223,428
Residential Builder and Developer [Member] | Revolving Loans [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	4,891
Other Commercial Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	8,117,333	7,336,861
Other Commercial Construction [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	7,172,389	7,092,799
Other Commercial Construction [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	859,518	211,292
Other Commercial Construction [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	85,426	32,770
Other Commercial Construction [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	85,560
Other Commercial Construction [Member] | Revolving Loans [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	80,428
Other Commercial Construction [Member] | Revolving Loans [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	5,132
Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	14,810,789	16,179,761	$ 11,519,760	$ 8,136,036	$ 6,816,987
Term Loans [Member] | Commercial, Financial, Leasing, etc. [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	8,260,467	2,667,683	1,959,629	1,164,002	948,621
Term Loans [Member] | Commercial, Financial, Leasing, etc. [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	7,944,081	2,571,703	1,744,756	1,074,677	878,129
Term Loans [Member] | Commercial, Financial, Leasing, etc. [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	313,697	88,164	164,361	64,980	50,254
Term Loans [Member] | Commercial, Financial, Leasing, etc. [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	2,689	7,816	50,512	24,345	20,238
Term Loans [Member] | Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	2,261,424	5,387,940	4,082,100	3,168,091	3,795,452
Term Loans [Member] | Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	2,055,007	4,937,718	3,679,741	3,005,081	3,131,570
Term Loans [Member] | Commercial [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	206,417	446,695	396,270	141,128	634,733
Term Loans [Member] | Commercial [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount		3,527	6,089	21,882	29,149
Term Loans [Member] | Residential Builder and Developer [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	289,977	539,743	270,765	68,978	15,314
Term Loans [Member] | Residential Builder and Developer [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	285,891	526,779	254,416	51,814	14,710
Term Loans [Member] | Residential Builder and Developer [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	4,086	12,964	16,349	17,164	302
Term Loans [Member] | Residential Builder and Developer [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount					302
Term Loans [Member] | Other Commercial Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	482,216	2,545,555	2,578,345	1,472,026	601,034
Term Loans [Member] | Other Commercial Construction [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	459,366	2,340,490	2,314,047	1,254,678	404,993
Term Loans [Member] | Other Commercial Construction [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	22,850	$ 205,065	$ 264,298	216,998	138,268
Term Loans [Member] | Other Commercial Construction [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount				$ 350	$ 57,773
Term Loans Prior Period [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	21,445,766
Term Loans Prior Period [Member] | Commercial, Financial, Leasing, etc. [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,710,939
Term Loans Prior Period [Member] | Commercial, Financial, Leasing, etc. [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,579,718
Term Loans Prior Period [Member] | Commercial, Financial, Leasing, etc. [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	82,987
Term Loans Prior Period [Member] | Commercial, Financial, Leasing, etc. [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	48,234
Term Loans Prior Period [Member] | Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	8,006,022
Term Loans Prior Period [Member] | Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	6,729,170
Term Loans Prior Period [Member] | Commercial [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,165,443
Term Loans Prior Period [Member] | Commercial [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	111,409
Term Loans Prior Period [Member] | Residential Builder and Developer [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	40,758
Term Loans Prior Period [Member] | Residential Builder and Developer [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	16,755
Term Loans Prior Period [Member] | Residential Builder and Developer [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	22,557
Term Loans Prior Period [Member] | Residential Builder and Developer [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,446
Term Loans Prior Period [Member] | Other Commercial Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	352,597
Term Loans Prior Period [Member] | Other Commercial Construction [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	318,387
Term Loans Prior Period [Member] | Other Commercial Construction [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	12,039
Term Loans Prior Period [Member] | Other Commercial Construction [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	$ 22,171

Loans and Leases and the Allo_9

Loans and Leases and the Allowance for Credit Losses - Summary of loans in Accrual and Nonaccrual Status (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Current	$ 95,447,143	$ 87,999,720
30-89 Days Past Due	618,000	1,174,132
Accruing Loans Past Due 90 Days or More	535,755	518,728
Nonaccrual	1,156,650	963,112
Loans and leases, net of unearned discount	97,757,548	90,922,869
Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	17,346,363
Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,502,086
Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Current	12,746,530	12,760,040
30-89 Days Past Due	218,870	451,274
Accruing Loans Past Due 90 Days or More	479,027	486,515
Nonaccrual	306,907	235,663
Loans and leases, net of unearned discount	13,751,334	14,082,425
Residential [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	53,040
30-89 Days Past Due	379
Nonaccrual	220
Loans and leases, net of unearned discount	53,639
Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
Current	1,715,896	1,858,037
30-89 Days Past Due	25,537	65,215
Accruing Loans Past Due 90 Days or More		181
Nonaccrual	118,695	83,427
Loans and leases, net of unearned discount	1,860,128	2,073,669
Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	4,107,387	4,386,511
30-89 Days Past Due	34,341	30,229
Nonaccrual	77,094	63,215
Loans and leases, net of unearned discount	4,218,822	4,481,617
Home Equity Lines and Loans [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	2,687,506
Nonaccrual	1,196
Loans and leases, net of unearned discount	2,688,702
Home Equity Lines and Loans [Member] | Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	1,348,093
30-89 Days Past Due	32,551
Nonaccrual	70,003
Loans and leases, net of unearned discount	1,450,647
Commercial Real Estate Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	6,342,914	5,484,997
30-89 Days Past Due	30,170	36,827
Nonaccrual	24,152	14,219
Loans and leases, net of unearned discount	6,397,236	5,536,142
Loans to Motor Vehicle [Member]
Financing Receivable Recorded Investment [Line Items]
Current	3,680,749	3,787,221
30-89 Days Past Due	41,375	78,478
Nonaccrual	42,736	21,293
Loans and leases, net of unearned discount	3,764,860	3,886,992
Other [Member]
Financing Receivable Recorded Investment [Line Items]
Current	1,346,276	1,395,240
30-89 Days Past Due	8,910	45,978
Accruing Loans Past Due 90 Days or More	3,919	5,156
Nonaccrual	42,750	3,512
Loans and leases, net of unearned discount	1,401,855	1,481,942
Other [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	915,187
30-89 Days Past Due	5,016
Accruing Loans Past Due 90 Days or More	3,628
Nonaccrual	35,103
Loans and leases, net of unearned discount	958,934
Other [Member] | Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	2,024
30-89 Days Past Due	557
Nonaccrual	311
Loans and leases, net of unearned discount	2,892
Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	14,810,789	16,179,761	$ 11,519,760	$ 8,136,036	$ 6,816,987
Term Loans [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Current	1,386,049	1,446,544	627,380	711,769	735,767
30-89 Days Past Due	2,291	7,259	6,718	20,267	4,256
Accruing Loans Past Due 90 Days or More	117	8,995	26,337	118,899	25,353
Nonaccrual	29	4,223	2,930	5,696	950
Loans and leases, net of unearned discount	1,388,486	1,467,021	663,365	856,631	766,326
Term Loans [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	852	4,931	2,550	2,731	155
30-89 Days Past Due		20
Loans and leases, net of unearned discount	852	4,951	2,550	2,731	155
Term Loans [Member] | Commercial Real Estate Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	1,453,572	2,021,651	1,055,732	728,343	410,077
30-89 Days Past Due	2,415	7,557	5,208	5,096	2,815
Nonaccrual	783	3,479	4,229	4,844	2,666
Loans and leases, net of unearned discount	1,456,770	2,032,687	1,065,169	738,283	415,558
Term Loans [Member] | Loans to Motor Vehicle [Member]
Financing Receivable Recorded Investment [Line Items]
Current	567,784	1,341,719	802,096	595,776	253,239
30-89 Days Past Due	1,495	9,879	10,557	10,642	5,590
Nonaccrual	1,125	7,176	10,987	11,054	7,058
Loans and leases, net of unearned discount	570,404	1,358,774	823,640	617,472	265,887
Term Loans [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Current	93,225	174,085	73,089	47,297	8,532
30-89 Days Past Due	1,246	778	557	311	56
Nonaccrual	5,722	544	551	214	52
Loans and leases, net of unearned discount	100,193	$ 175,407	$ 74,197	$ 47,822	$ 8,640
Term Loans Prior Period [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	21,445,766
Term Loans Prior Period [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Current	7,785,981
30-89 Days Past Due	177,700
Accruing Loans Past Due 90 Days or More	299,326
Nonaccrual	292,859
Loans and leases, net of unearned discount	8,555,866
Term Loans Prior Period [Member] | Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
Current	1,715,896
30-89 Days Past Due	25,537
Nonaccrual	118,695
Loans and leases, net of unearned discount	1,860,128
Term Loans Prior Period [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	60,569
30-89 Days Past Due	1,770
Nonaccrual	5,895
Loans and leases, net of unearned discount	68,234
Term Loans Prior Period [Member] | Commercial Real Estate Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Current	673,539
30-89 Days Past Due	7,079
Nonaccrual	8,151
Loans and leases, net of unearned discount	688,769
Term Loans Prior Period [Member] | Loans to Motor Vehicle [Member]
Financing Receivable Recorded Investment [Line Items]
Current	120,135
30-89 Days Past Due	3,212
Nonaccrual	5,336
Loans and leases, net of unearned discount	128,683
Term Loans Prior Period [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Current	32,837
30-89 Days Past Due	389
Accruing Loans Past Due 90 Days or More	291
Nonaccrual	253
Loans and leases, net of unearned discount	$ 33,770

Loans and Leases and the All_10

Loans and Leases and the Allowance for Credit Losses - Summary of Loan Grades (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	$ 97,757,548	$ 90,922,869
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	29,203,862	23,838,168
Commercial, Financial, Leasing, etc. [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	27,276,595	22,595,821
Commercial, Financial, Leasing, etc. [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,642,613	895,790
Commercial, Financial, Leasing, etc. [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	284,654	346,557
Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	27,588,264	26,657,808
Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	24,383,155	25,728,725
Commercial [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	3,032,621	770,609
Commercial [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	172,488	158,474
Residential Builder and Developer [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,453,854	1,547,245
Residential Builder and Developer [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,373,793	1,419,162
Residential Builder and Developer [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	78,313	124,101
Residential Builder and Developer [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,748	3,982
Other Commercial Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	8,117,333	7,336,861
Other Commercial Construction [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	7,172,389	7,092,799
Other Commercial Construction [Member] | Criticized Accrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	859,518	211,292
Other Commercial Construction [Member] | Criticized Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	$ 85,426	$ 32,770

Loans and Leases and the All_11

Loans and Leases and the Allowance for Credit Losses - Changes in Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	$ 1,384,366	$ 1,019,337	$ 1,051,071	$ 1,019,444
Provision for credit losses	325,000	55,000	575,000	77,000
Net charge-offs
Charge-offs	(91,397)	(69,406)	(159,101)	(114,506)
Recoveries	20,267	24,936	38,809	47,929
Net (charge-offs) recoveries	(71,130)	(44,470)	(120,292)	(66,577)
Ending balance	1,638,236	1,029,867	1,638,236	1,029,867
Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Net charge-offs
Adoption of new accounting standard			132,457
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	358,092	335,620	366,094	330,055
Provision for credit losses	69,400	10,337	135,994	16,608
Net charge-offs
Charge-offs	(32,608)	(16,608)	(48,991)	(25,108)
Recoveries	3,373	6,506	6,634	14,300
Net (charge-offs) recoveries	(29,235)	(10,102)	(42,357)	(10,808)
Ending balance	398,257	335,855	398,257	335,855
Commercial, Financial, Leasing, etc. [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Net charge-offs
Adoption of new accounting standard			(61,474)
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	433,689	337,995	322,201	341,655
Provision for credit losses	159,090	14,501	247,756	10,298
Net charge-offs
Charge-offs	(17,472)	(10,165)	(18,744)	(10,448)
Recoveries	1,014	965	1,452	1,791
Net (charge-offs) recoveries	(16,458)	(9,200)	(17,292)	(8,657)
Ending balance	576,321	343,296	576,321	343,296
Commercial Real Estate [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Net charge-offs
Adoption of new accounting standard			23,656
One-to-Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	115,792	65,136	56,033	69,125
Provision for credit losses	2,850	(2,376)	12,141	(4,823)
Net charge-offs
Charge-offs	(1,609)	(3,263)	(6,711)	(6,635)
Recoveries	1,888	1,514	3,562	3,344
Net (charge-offs) recoveries	279	(1,749)	(3,149)	(3,291)
Ending balance	118,921	61,011	118,921	61,011
One-to-Four Family Residential [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Net charge-offs
Adoption of new accounting standard			53,896
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	476,793	203,045	229,118	200,564
Provision for credit losses	93,660	31,594	179,109	54,477
Net charge-offs
Charge-offs	(39,708)	(39,370)	(84,655)	(72,315)
Recoveries	13,992	15,951	27,161	28,494
Net (charge-offs) recoveries	(25,716)	(23,419)	(57,494)	(43,821)
Ending balance	$ 544,737	211,220	544,737	211,220
Consumer [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Net charge-offs
Adoption of new accounting standard			194,004
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance		77,541	77,625	78,045
Provision for credit losses		944		440
Net charge-offs
Ending balance		$ 78,485		$ 78,485
Unallocated [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Net charge-offs
Adoption of new accounting standard			$ (77,625)

Loans and Leases and the All_12

Loans and Leases and the Allowance for Credit Losses - Loan and Leases Considered Nonaccrual and Interest Income Recognized on Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Jan. 01, 2020	Mar. 31, 2019	Jan. 01, 2019
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	$ 446,591	$ 362,169	$ 446,591	$ 362,169
Amortized Cost without Allowance	710,059	503,215	710,059	503,215
Total	1,156,650	865,384	1,156,650	865,384
Amortized Cost					$ 1,061,748	$ 1,134,333	$ 881,611	$ 893,608
Interest Income Recognized	18,127	11,573	30,698	22,050
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	138,556	150,974	138,556	150,974
Amortized Cost without Allowance	146,098	72,759	146,098	72,759
Total	284,654	223,733	284,654	223,733
Amortized Cost					286,647	346,743	245,819	234,423
Interest Income Recognized	1,298	3,635	3,036	6,716
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	57,675	52,443	57,675	52,443
Amortized Cost without Allowance	114,813	150,673	114,813	150,673
Total	172,488	203,116	172,488	203,116
Amortized Cost					188,469	173,796	207,709	203,672
Interest Income Recognized	4,697	2,314	5,789	3,410
Residential Builder and Developer [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	1,748	1,429	1,748	1,429
Amortized Cost without Allowance		4,556		4,556
Total	1,748	5,985	1,748	5,985
Amortized Cost					3,204	4,708	4,392	4,798
Interest Income Recognized	11	35	59	219
Other Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	42,969	25,572	42,969	25,572
Amortized Cost without Allowance	42,457	7,197	42,457	7,197
Total	85,426	32,769	85,426	32,769
Amortized Cost					34,935	35,881	19,899	22,205
Interest Income Recognized	5,716	544	6,577	1,181
Residential [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	80,772	57,323	80,772	57,323
Amortized Cost without Allowance	226,135	153,599	226,135	153,599
Total	306,907	210,922	306,907	210,922
Amortized Cost					293,638	322,504	210,266	233,352
Interest Income Recognized	5,029	2,990	11,848	6,589
Residential Limited Documentation [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	26,460	25,796	26,460	25,796
Amortized Cost without Allowance	92,235	61,755	92,235	61,755
Total	118,695	87,551	118,695	87,551
Amortized Cost					119,317	114,667	84,863	84,685
Interest Income Recognized	256	274	457	526
Home Equity Lines and Loans [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	38,890	25,530	38,890	25,530
Amortized Cost without Allowance	38,204	41,397	38,204	41,397
Total	77,094	66,927	77,094	66,927
Amortized Cost					63,071	65,039	69,245	71,292
Interest Income Recognized	760	1,461	2,219	2,771
Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	16,264	6,493	16,264	6,493
Amortized Cost without Allowance	7,888	4,660	7,888	4,660
Total	24,152	11,153	24,152	11,153
Amortized Cost					13,405	14,308	10,972	11,199
Interest Income Recognized	154	142	306	284
Loans to Motor Vehicle [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	35,510	13,852	35,510	13,852
Amortized Cost without Allowance	7,226	6,318	7,226	6,318
Total	42,736	20,170	42,736	20,170
Amortized Cost					19,251	21,293	21,209	23,359
Interest Income Recognized	45	53	92	107
Other [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	7,747	2,757	7,747	2,757
Amortized Cost without Allowance	35,003	301	35,003	301
Total	42,750	3,058	42,750	3,058
Amortized Cost					$ 39,811	$ 35,394	$ 7,237	$ 4,623
Interest Income Recognized	$ 161	$ 125	$ 315	$ 247

Loans and Leases and the All_13

Loans and Leases and the Allowance for Credit Losses - Loan Modification Activities that were Considered Troubled Debt Restructurings (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)Modification	Jun. 30, 2019USD ($)Modification	Jun. 30, 2020USD ($)Modification	Jun. 30, 2019USD ($)Modification
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	2,394	93	2,490	225
Pre-modification Recorded Investment	$ 152,872	$ 23,577	$ 219,374	$ 70,114
Post- modification	143,300	23,958	209,817	70,249
Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	69,139	7,669	82,158	18,593
Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	333		333
Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	37,423	$ 16,289	90,921	$ 51,656
Other [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	$ 36,405		$ 36,405
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	135	24	167	89
Pre-modification Recorded Investment	$ 55,136	$ 2,597	$ 67,828	$ 33,212
Post- modification	54,670	2,558	66,723	33,302
Commercial, Financial, Leasing, etc. [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	17,551	667	22,617	7,141
Commercial, Financial, Leasing, etc. [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	5,514	$ 1,891	12,501	$ 26,161
Commercial, Financial, Leasing, etc. [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	$ 31,605		$ 31,605
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	46	14	56	29
Pre-modification Recorded Investment	$ 41,872	$ 10,340	$ 81,514	$ 19,581
Post- modification	31,992	10,218	69,315	19,172
Commercial Real Estate [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	10,511	2,577	11,866	3,564
Commercial Real Estate [Member] | Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	333		333
Commercial Real Estate [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	16,348	$ 7,641	52,316	$ 15,608
Commercial Real Estate [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	$ 4,800		$ 4,800
Residential Builder and Developer [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	1		1	2
Pre-modification Recorded Investment	$ 91		$ 91	$ 1,330
Post- modification	90		90	1,068
Residential Builder and Developer [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification				$ 1,068
Residential Builder and Developer [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	$ 90		$ 90
Other Commercial Construction [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification		1		2
Pre-modification Recorded Investment		$ 1,038		$ 1,456
Post- modification		1,033		1,399
Other Commercial Construction [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification		$ 1,033		$ 1,399
Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	25	26	52	43
Pre-modification Recorded Investment	$ 8,872	$ 7,513	$ 19,050	$ 11,329
Post- modification	9,634	8,042	21,858	12,066
Residential [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	3,101	4,008	6,348	5,759
Residential [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	$ 6,533	$ 4,034	$ 15,510	$ 6,307
Residential Limited Documentation [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification		2	9	3
Pre-modification Recorded Investment		$ 612	$ 2,980	$ 848
Post- modification		625	3,899	864
Residential Limited Documentation [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification		160	2,667	399
Residential Limited Documentation [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification		$ 465	$ 1,232	$ 465
Home Equity Lines and Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	120	13	126	20
Pre-modification Recorded Investment	$ 7,571	$ 1,273	$ 8,309	$ 1,749
Post- modification	7,584	1,278	8,330	1,769
Home Equity Lines and Loans [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	147	53	559	90
Home Equity Lines and Loans [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	$ 7,437	$ 1,225	$ 7,771	$ 1,679
Commercial Real Estate Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	271	1	274	5
Pre-modification Recorded Investment	$ 10,795	$ 15	$ 10,885	$ 103
Post- modification	10,795	15	10,885	103
Commercial Real Estate Loans [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	$ 10,795	$ 15	$ 10,885	$ 103
Loans to Motor Vehicle [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	1,461	12	1,470	32
Pre-modification Recorded Investment	$ 26,352	$ 189	$ 26,534	$ 506
Post- modification	26,352	189	26,534	506
Loans to Motor Vehicle [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	$ 26,352	$ 189	$ 26,534	469
Loans to Motor Vehicle [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification				$ 37
Other [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	335		335
Pre-modification Recorded Investment	$ 2,183		$ 2,183
Post- modification	2,183		2,183
Other [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	682		682
Other [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Post- modification	$ 1,501		$ 1,501

Borrowings - Additional Informa

Borrowings - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Debt Instruments [Abstract]
Junior subordinated debentures	$ 527
Debt Maturity, Start Year	Jan. 1, 2027
Debt Maturity, End Year	Dec. 31, 2033
Agreements to repurchase securities	$ 100	$ 102
Collateral posted	$ 107	$ 108

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Additional Information (Detail1)	Jun. 30, 2020
Maximum [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-07-01
Disaggregation Of Revenue [Line Items]
Period of satisfaction of contract with customer	1 year

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Additional Information (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Uncollected amounts receivable	$ 60	$ 62
Accrued interest and other liabilities [Member]
Disaggregation Of Revenue [Line Items]
Deferred revenue	$ 42	$ 43

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Summary of Sources of Noninterest Income that are Subject to Noted Accounting Guidance (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Brokerage services income	$ 10,463	$ 12,478	$ 23,592	$ 24,954
Other revenues from operations:
Total other income	487,273	512,095	1,016,633	1,012,860
Total other income	487,273	512,095	1,016,633	1,012,860
Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	77,455	107,787	183,616	210,899
Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	151,882	144,382	300,633	277,168
ASU 2014-09 [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	10,463	12,478	23,592	24,954
Other revenues from operations:
Merchant discount and credit card fees	21,055	28,688	48,222	53,826
Other	15,764	25,423	39,070	48,660
Total other income	276,619	318,758	595,133	615,507
Merchant discount and credit card fees	21,055	28,688	48,222	53,826
Other	15,764	25,423	39,070	48,660
Total other income	276,619	318,758	595,133	615,507
ASU 2014-09 [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	77,455	107,787	183,616	210,899
ASU 2014-09 [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	151,882	144,382	300,633	277,168
ASU 2014-09 [Member] | Business Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	8,159	9,895	18,490	18,777
Total other income	19,436	25,077	45,029	49,073
Merchant discount and credit card fees	8,159	9,895	18,490	18,777
Total other income	19,436	25,077	45,029	49,073
ASU 2014-09 [Member] | Business Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	11,271	15,175	26,521	30,284
ASU 2014-09 [Member] | Business Banking [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	6	7	18	12
ASU 2014-09 [Member] | Commercial Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	8,891	13,129	22,207	25,221
Other	787	3,145	2,973	4,147
Total other income	32,329	39,592	72,292	76,110
Merchant discount and credit card fees	8,891	13,129	22,207	25,221
Other	787	3,145	2,973	4,147
Total other income	32,329	39,592	72,292	76,110
ASU 2014-09 [Member] | Commercial Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	22,514	23,094	46,671	46,304
ASU 2014-09 [Member] | Commercial Banking [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	137	224	441	438
ASU 2014-09 [Member] | Commercial Real Estate [Member]
Other revenues from operations:
Merchant discount and credit card fees	379	496	1,228	1,102
Other	1,188	2,680	2,031	4,468
Total other income	4,132	5,538	8,636	10,458
Merchant discount and credit card fees	379	496	1,228	1,102
Other	1,188	2,680	2,031	4,468
Total other income	4,132	5,538	8,636	10,458
ASU 2014-09 [Member] | Commercial Real Estate [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	2,565	2,362	5,377	4,888
ASU 2014-09 [Member] | Discretionary Portfolio [Member]
Other revenues from operations:
Other	150	641	1,007	1,042
Total other income	150	641	1,007	1,042
Other	150	641	1,007	1,042
Total other income	150	641	1,007	1,042
ASU 2014-09 [Member] | Residential Mortgage Banking [Member]
Other revenues from operations:
Other	1,052	1,033	1,974	2,097
Total other income	1,052	1,035	1,974	2,101
Other	1,052	1,033	1,974	2,097
Total other income	1,052	1,035	1,974	2,101
ASU 2014-09 [Member] | Residential Mortgage Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer		2		4
ASU 2014-09 [Member] | Retail Banking [Member]
Other revenues from operations:
Merchant discount and credit card fees	3,450	4,566	5,721	7,704
Other	3,166	9,329	9,148	17,823
Total other income	46,640	79,556	116,563	152,339
Merchant discount and credit card fees	3,450	4,566	5,721	7,704
Other	3,166	9,329	9,148	17,823
Total other income	46,640	79,556	116,563	152,339
ASU 2014-09 [Member] | Retail Banking [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	40,024	65,661	101,694	126,812
ASU 2014-09 [Member] | All Other [Member]
Disaggregation Of Revenue [Line Items]
Brokerage services income	10,463	12,478	23,592	24,954
Other revenues from operations:
Merchant discount and credit card fees	176	602	576	1,022
Other	9,421	8,595	21,937	19,083
Total other income	172,880	167,319	349,632	324,384
Merchant discount and credit card fees	176	602	576	1,022
Other	9,421	8,595	21,937	19,083
Total other income	172,880	167,319	349,632	324,384
ASU 2014-09 [Member] | All Other [Member] | Service Charges on Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	1,081	1,493	3,353	2,607
ASU 2014-09 [Member] | All Other [Member] | Trust Income [Member]
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer	$ 151,739	$ 144,151	$ 300,174	$ 276,718

Pension Plans and Other Postr_3

Pension Plans and Other Postretirement Benefits - Net Periodic Defined Benefit Cost for Defined Benefit Plans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5,258	$ 4,559	$ 9,972	$ 8,646
Interest cost on projected benefit obligation	17,824	20,590	35,710	40,790
Expected return on plan assets	(31,281)	(30,470)	(62,756)	(61,070)
Amortization of prior service cost (credit)	154	154	279	279
Amortization of net actuarial loss (gain)	15,098	6,546	29,048	10,996
Net periodic cost (benefit)	7,053	1,379	12,253	(359)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	262	229	485	429
Interest cost on projected benefit obligation	451	569	870	1,172
Amortization of prior service cost (credit)	(1,194)	(1,190)	(2,369)	(2,365)
Amortization of net actuarial loss (gain)	(318)	(323)	(618)	(623)
Net periodic cost (benefit)	$ (799)	$ (715)	$ (1,632)	$ (1,387)

Pension Plans and Other Postr_4

Pension Plans and Other Postretirement Benefits - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Compensation And Retirement Disclosure [Abstract]
Defined contribution pension and retirement savings plans total expense	$ 23	$ 19	$ 51	$ 41

Earnings Per Common Share - Com

Earnings Per Common Share - Computations of Basic Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income available to common shareholders:
Net income	$ 241,054	$ 473,260	$ 509,876	$ 956,002
Less: Preferred stock dividends	(17,050)	(18,130)	(34,128)	(36,260)
Net income available to common equity	224,004	455,130	475,748	919,742
Less: Income attributable to unvested stock-based compensation awards	(906)	(2,498)	(1,954)	(5,024)
Net income available to common shareholders	$ 223,098	$ 452,632	$ 473,794	$ 914,718
Weighted-average shares outstanding:
Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards	129,059	136,182	129,750	137,403
Less: Unvested stock-based compensation awards	(784)	(749)	(764)	(749)
Weighted-average shares outstanding	128,275	135,433	128,986	136,654
Basic earnings per common share	$ 1.74	$ 3.34	$ 3.67	$ 6.69

Earnings Per Common Share - C_2

Earnings Per Common Share - Computations of Diluted Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income available to common equity	$ 224,004	$ 455,130	$ 475,748	$ 919,742
Less: Income attributable to unvested stock-based compensation awards	(905)	(2,497)	(1,953)	(5,023)
Net income available to common shareholders	$ 223,099	$ 452,633	$ 473,795	$ 914,719
Adjusted weighted-average shares outstanding:
Common and unvested stock-based compensation awards	129,059	136,182	129,750	137,403
Less: Unvested stock-based compensation awards	(784)	(749)	(764)	(749)
Plus: Incremental shares from assumed conversion of stock-based compensation awards and warrants to purchase common stock	58	31	58	31
Adjusted weighted-average shares outstanding	128,333	135,464	129,044	136,685
Diluted earnings per common share	$ 1.74	$ 3.34	$ 3.67	$ 6.69

Earnings Per Common Share - Add

Earnings Per Common Share - Additional Information (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share	483,491	115,293	474,093	197,598

Comprehensive Income - Componen

Comprehensive Income - Components of Other Comprehensive Income (Loss) and Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) to Net Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax			$ (279,959)	$ (569,328)
Unrealized holding gains (losses), net, before tax			177,086	207,802
Foreign currency translation adjustment, before tax			(3,624)	(507)
Unrealized gains (losses) on cash flow hedges, before tax			511,195	188,272
Total other comprehensive income (loss) before reclassifications, before tax			684,657	395,567
Amortization of unrealized holding losses on held-to-maturity ("HTM") securities, before tax			1,619	1,691
Accretion of net gain on terminated cash flow hedges, before tax			(64)	(56)
Net yield adjustment from cash flow hedges currently in effect, before tax			(101,194)	11,176
Amortization of prior service credit, before tax			(2,090)	(2,086)
Amortization of actuarial losses, before tax			28,430	10,373
Total other comprehensive income (loss), before tax			611,358	416,672
Ending balance, before tax	$ 331,399	$ (152,656)	331,399	(152,656)
Losses realized in net income, before tax				7
Beginning balance, tax			73,279	149,247
Unrealized holding gains (losses), net, tax			(45,856)	(54,609)
Foreign currency translation adjustment, tax			630	107
Unrealized gains (losses) on cash flow hedges, tax			(132,404)	(49,497)
Total other comprehensive income (loss) before reclassifications, tax			(177,630)	(103,999)
Amortization of unrealized holding losses on held-to-maturity ('HTM') securities, tax			(450)	(445)
Accretion of net gain on terminated cash flow hedges, tax			18	14
Net yield adjustment from cash flow hedges currently in effect, tax			26,210	(2,938)
Amortization of prior service credit, tax			650	548
Amortization of actuarial losses, tax			(8,846)	(2,727)
Total other comprehensive income (loss), tax			(160,048)	(109,549)
Ending balance, tax	(86,769)	39,698	(86,769)	39,698
Losses realized in net income, tax				(2)
Beginning balance, net of tax			(206,680)	(420,081)
Unrealized holding gains (losses), net of tax			131,230	153,193
Foreign currency translation adjustment	(51)	(675)	(2,994)	(400)
Unrealized gains (losses) on cash flow hedges, net of tax			378,791	138,775
Total other comprehensive income (loss) before reclassifications, net of tax			507,027	291,568
Amortization of unrealized holding losses on held-to-maturity ('HTM') securities, net of tax			1,169	1,246
Accretion of net gain on terminated cash flow hedges, net of tax			(46)	(42)
Net yield adjustment from cash flow hedges currently in effect, net of tax			(74,984)	8,238
Amortization of prior service credit, net of tax			(1,440)	(1,538)
Amortization of actuarial losses, net of tax			19,584	7,646
Total other comprehensive income	34,797	175,051	451,310	307,123
Ending balance, net of tax	244,630	(112,958)	244,630	(112,958)
Losses realized in net income, net of tax				5
Investment Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax			50,701	(200,107)
Unrealized holding gains (losses), net, before tax			177,086	207,802
Total other comprehensive income (loss) before reclassifications, before tax			177,086	207,802
Amortization of unrealized holding losses on held-to-maturity ("HTM") securities, before tax			1,619	1,691
Total other comprehensive income (loss), before tax			178,705	209,500
Ending balance, before tax	229,406	9,393	229,406	9,393
Losses realized in net income, before tax				7
Total other comprehensive income			132,399
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax			(464,548)	(354,502)
Amortization of prior service credit, before tax			(2,090)	(2,086)
Amortization of actuarial losses, before tax			28,430	10,373
Total other comprehensive income (loss), before tax			26,340	8,287
Ending balance, before tax	(438,208)	(346,215)	(438,208)	(346,215)
Total other comprehensive income			18,144
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax			133,888	(14,719)
Foreign currency translation adjustment, before tax			(3,624)	(507)
Unrealized gains (losses) on cash flow hedges, before tax			511,195	188,272
Total other comprehensive income (loss) before reclassifications, before tax			507,571	187,765
Accretion of net gain on terminated cash flow hedges, before tax			(64)	(56)
Net yield adjustment from cash flow hedges currently in effect, before tax			(101,194)	11,176
Total other comprehensive income (loss), before tax			406,313	198,885
Ending balance, before tax	$ 540,201	$ 184,166	$ 540,201	$ 184,166

Comprehensive Income - Accumula

Comprehensive Income - Accumulated Other Comprehensive Income (Loss), Net (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 15,815,794	$ 15,587,529	$ 15,716,649	$ 15,460,191
Net gain during period	34,797	175,051	451,310	307,123
Ending balance	15,945,105	15,691,827	15,945,105	15,691,827
Investment Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			37,380
Net gain during period			132,399
Ending balance	169,779		169,779
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(342,419)
Net gain during period			18,144
Ending balance	(324,275)		(324,275)
Cash Flow Hedges and Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			98,359
Net gain during period			300,767
Ending balance	399,126		399,126
Accumulated Other Comprehensive Income (Loss), Net [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	209,833	(288,009)	(206,680)	(420,081)
Net gain during period			451,310
Ending balance	$ 244,630	$ (112,958)	$ 244,630	$ (112,958)

Derivative Financial Instrume_3

Derivative Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	$ 57,300,000,000		$ 57,300,000,000		$ 57,550,000,000
Net unrealized pre-tax gains related to hedged loans held for sale, commitments to originate loans for sale and commitments to sell loans	57,000,000		57,000,000		18,000,000
Aggregate fair value of derivative financial instruments in a liability position	143,000,000		143,000,000		51,000,000
Aggregate fair value of derivative financial instruments in asset position	1,000,000		1,000,000		6,000,000
Net fair value of derivative financial instruments in a net asset position	1,000,000		1,000,000		6,000,000
Collateral relating to net asset positions	81,000		81,000		5,000,000
Counterparties [Member]
Derivative [Line Items]
Post collateral requirements relating to positions	139,000,000		139,000,000		50,000,000
Clearinghouse Credit Facilities [Member]
Derivative [Line Items]
Amount of initial margin posted	124,000,000		124,000,000		84,000,000
Interest Rate Swap Agreements [Member]
Derivative [Line Items]
Increase decrease in net interest income due to interest rate swap agreements	81,000,000	$ 11,000,000	117,000,000	$ 24,000,000
Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	37,100,000,000		37,100,000,000		48,600,000,000
Foreign Currency and Other Option and Futures Contracts [Member]
Derivative [Line Items]
Notional amounts of derivative contracts entered into for trading account purposes	$ 1,000,000,000		$ 1,000,000,000		$ 1,200,000,000

Derivative Financial Instrume_4

Derivative Financial Instruments - Information about Interest Rate Swap Agreements (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Notional Amount	$ 57,300,000,000	$ 57,550,000,000
Average Maturity (in years)	1 year 3 months 19 days	1 year 6 months
Estimated Fair Value Gain (Loss)	$ (249,000)	$ (1,762,000)
Interest Payments On Variable Rate Commercial Real Estate Loans [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Notional Amount	$ 54,250,000,000	$ 53,750,000,000
Average Maturity (in years)	1 year 3 months 19 days	1 year 4 months 24 days
Weighted-Average Rate, Fixed	2.55%	2.44%
Weighted-Average Rate, Variable	0.18%	1.73%
Estimated Fair Value Gain (Loss)	$ 220,000	$ (1,195,000)
Fixed Rate Long-Term Borrowings [Member] | Fair Value Hedges [Member]
Derivative [Line Items]
Notional Amount	$ 3,050,000,000	$ 3,800,000,000
Average Maturity (in years)	2 years 2 months 12 days	2 years 2 months 12 days
Weighted-Average Rate, Fixed	2.61%	2.51%
Weighted-Average Rate, Variable	0.72%	2.27%
Estimated Fair Value Gain (Loss)	$ (469,000)	$ (567,000)

Derivative Financial Instrume_5

Derivative Financial Instruments - Information about Interest Rate Swap Agreements (Parenthetical) (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Notional Amount	$ 57,300,000,000	$ 57,550,000,000
Forward-Starting Interest Rate Swap Agreements [Member]
Derivative [Line Items]
Notional Amount	40,900,000,000	40,400,000,000
Fair Value Hedges [Member]
Derivative [Line Items]
Reduction of estimated fair value losses on hedging instruments	133,800,000	45,100,000
Cash Flow Hedges [Member]
Derivative [Line Items]
Reduction of estimated fair value losses on hedging instruments	$ 549,300,000	$ 140,700,000

Derivative Financial Instrume_6

Derivative Financial Instruments - Information about Fair Values of Derivative Instruments in Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	$ 1,290,680	$ 427,267
Liability Derivatives, Fair Value	154,971	87,091
Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	1,287,389	425,840
Liability Derivatives, Fair Value	146,141	84,676
Fair Value Hedges [Member] | Derivatives Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	3,291	1,427
Liability Derivatives, Fair Value	8,830	2,415
Interest Rate Swap Agreements [Member] | Fair Value Hedges [Member] | Derivatives Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	818	232
Liability Derivatives, Fair Value	1,067	1,994
Commitments to Sell Real Estate Loans [Member] | Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	2,253	3,074
Liability Derivatives, Fair Value	7,526	3,548
Commitments to Sell Real Estate Loans [Member] | Fair Value Hedges [Member] | Derivatives Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	2,473	1,195
Liability Derivatives, Fair Value	7,763	421
Mortgage-Related Commitments to Originate Real Estate Loans for Sale [Member] | Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	40,727	11,965
Liability Derivatives, Fair Value	621	1,225
Interest Rate Contracts [Member] | Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	1,231,484	398,295
Liability Derivatives, Fair Value	127,008	68,103
Foreign Exchange and Other Option and Futures Contracts [Member] | Derivatives Not Designated and Qualifying as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	12,925	12,506
Liability Derivatives, Fair Value	$ 10,986	$ 11,800

Derivative Financial Instrume_7

Derivative Financial Instruments - Information about Fair Values of Derivative Instruments in Consolidated Balance Sheet (Parenthetical) (Detail) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Offsetting [Abstract]
Reduction in estimated fair value of interest rate contracts in asset position	$ (3.1)	$ (43.3)
Reduction in estimated fair value of interest rate contracts in liability position	$ (1,000)	$ (281.3)

Derivative Financial Instrume_8

Derivative Financial Instruments - Information about Fair Values of Derivative Instruments in Consolidated Statement of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives not designated as hedging instruments, Derivatives	$ 1,695	$ 10,972	$ 18,833	$ 15,296
Interest Rate Swap Agreements [Member] | Fixed Rate Long-Term Borrowings [Member] | Derivatives Designated and Qualifying as Hedging Instruments [Member] | Fair Value Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives in fair value hedging relationships, Derivatives	117	56,679	88,827	90,859
Derivatives in fair value hedging relationships, Hedged item	(605)	(56,458)	(88,429)	(90,472)
Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives not designated as hedging instruments, Derivatives	978	8,493	13,764	11,204
Foreign Exchange and Other Option and Futures Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives not designated as hedging instruments, Derivatives	$ 717	$ 2,479	$ 5,069	$ 4,092

Derivative Financial Instrume_9

Derivative Financial Instruments - Information about Hedged Items Included in Consolidated Balance Sheet (Detail) - Long-term Debt [Member] - Derivatives Designated and Qualifying as Hedging Instruments [Member] - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Carrying Amount [Member]
Derivatives, Fair Value [Line Items]
Hedged Item	$ 3,180,022	$ 3,840,775
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member]
Derivatives, Fair Value [Line Items]
Hedged Item	$ 132,069	$ 43,640

Variable Interest Entities an_2

Variable Interest Entities and Asset Securitizations - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Loss on securitization of assets			$ 0	$ 0
Other assets for its "investment" in the common securities recognized by the company of various trusts	$ 23,000,000		23,000,000		$ 23,000,000
Total assets of partnerships in which the company invested	139,536,969,000		139,536,969,000		119,872,757,000
Investment in partnership carrying amount	745,000,000		745,000,000		748,000,000
Unfunded commitments includes carrrying amount of its investments	363,000,000		363,000,000		414,000,000
Maximum exposure to loss of investments in real estate partnerships	957,000,000		957,000,000
Investments amortized to income tax expense	22,000,000	$ 17,000,000	43,000,000	34,000,000
Federal tax credits and other federal tax benefits recognized	26,000,000	$ 21,000,000	52,000,000	$ 41,000,000
Variable Interest Entity Primary Beneficiary [Member]
Total assets of partnerships in which the company invested	$ 2,000,000,000		$ 2,000,000,000		$ 1,500,000,000

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Estimated Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	$ 5,821,274	$ 6,318,776
U.S. Treasury and Federal Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	9,893	9,767
Obligations of States and Political Subdivisions [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	511	775
Government Issued or Guaranteed [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	5,690,161	6,180,940
Other Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	120,693	127,278
Fair Value Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading account assets	1,293,534	470,129
Investment securities	5,821,274	6,318,776
Equity securities	93,611	140,041
Real estate loans held for sale	695,969	442,079
Other assets	46,271	16,466
Total assets	7,950,659	7,387,491
Trading account liabilities	137,994	79,903
Other liabilities	16,977	7,188
Total liabilities	154,971	87,091
Fair Value Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading account assets	48,741	49,040
Equity securities	67,888	100,637
Total assets	116,629	149,677
Fair Value Measurements, Recurring [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading account assets	1,244,793	421,089
Investment securities	5,821,258	6,318,760
Equity securities	25,723	39,404
Real estate loans held for sale	695,969	442,079
Other assets	5,544	4,501
Total assets	7,793,287	7,225,833
Trading account liabilities	137,994	79,903
Other liabilities	16,356	5,963
Total liabilities	154,350	85,866
Fair Value Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	16	16
Other assets	40,727	11,965
Total assets	40,743	11,981
Other liabilities	621	1,225
Total liabilities	621	1,225
Fair Value Measurements, Recurring [Member] | U.S. Treasury and Federal Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	9,893	9,767
Fair Value Measurements, Recurring [Member] | U.S. Treasury and Federal Agencies [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	9,893	9,767
Fair Value Measurements, Recurring [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	511	775
Fair Value Measurements, Recurring [Member] | Obligations of States and Political Subdivisions [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	511	775
Fair Value Measurements, Recurring [Member] | Government Issued or Guaranteed [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	5,690,161	6,180,940
Fair Value Measurements, Recurring [Member] | Government Issued or Guaranteed [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	5,690,161	6,180,940
Fair Value Measurements, Recurring [Member] | Privately Issued Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	16	16
Fair Value Measurements, Recurring [Member] | Privately Issued Mortgage-Backed Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	16	16
Fair Value Measurements, Recurring [Member] | Other Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	120,693	127,278
Fair Value Measurements, Recurring [Member] | Other Debt Securities [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investment securities	$ 120,693	$ 127,278

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Level 3 Assets and Liabilities Measured at Estimated Fair Value on Recurring Basis (Detail) - Fair Value Measurements, Recurring [Member] - Significant Unobservable Inputs (Level 3) [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Privately Issued Mortgage-Backed Securities [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 16	$ 16	$ 16	$ 22
Total gains realized/unrealized:
Settlements				(6)
Ending Balance	16	16	16	16
Other Assets and Other Liabilities [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	35,027	7,433	10,740	7,712
Total gains realized/unrealized:
Included in earnings	48,732	36,463	92,813	53,009
Transfers out of Level 3	(43,653)	(26,696)	(63,447)	(43,521)
Ending Balance	40,106	17,200	40,106	17,200
Changes in unrealized gains included in earnings related to assets still held at end of period	$ 33,725	$ 17,464	$ 38,514	$ 17,372

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurement Input [Extensible List]	us-gaap:MeasurementInputComparabilityAdjustmentMember		us-gaap:MeasurementInputComparabilityAdjustmentMember
Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rates for fair value estimations			15.00%
Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rates for fair value estimations			90.00%
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Change in fair value of nonrecurring fair value measured loans for charge-offs and impairment reserves	$ 50	$ 20	$ 50	$ 36
Significant Unobservable Inputs (Level 3) [Member] | Residential Mortgage Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Capitalized servicing rights	177		177		$ 188
Capitalized servicing rights, valuation allowance			27		$ 7
Changes in fair value recognized for impairment of capitalized servicing rights	10	9	$ 20	9
Weighted-average prepayment speeds			18.03%		18.50%
Discounted rate represented weighted-average option-adjusted basis spread point percentage			900.00%		900.00%
Fair Value, Measurements, Nonrecurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loans measured at fair value on nonrecurring basis	248	212	$ 248	212	$ 305
Assets taken in foreclosure of defaulted loans measured at fair value on a nonrecurring basis	31	17	31	17
Fair Value, Measurements, Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loans measured at fair value on nonrecurring basis	145	155	145	155	115
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Loans measured at fair value on nonrecurring basis	$ 103	$ 57	$ 103	$ 57	$ 190

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information Related to Significant Unobservable Inputs (Detail) - Fair Value Measurements, Recurring [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Discounted Cash Flows | Other Assets and Other Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Recurring fair value measurements	$ 40,106	$ 10,740
Discounted Cash Flows | Other Assets and Other Liabilities [Member] | Minimum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Commitment expirations	0.00%	0.00%
Discounted Cash Flows | Other Assets and Other Liabilities [Member] | Maximum [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Commitment expirations	100.00%	99.00%
Discounted Cash Flows | Other Assets and Other Liabilities [Member] | Weighted Average [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Commitment expirations	19.00%	13.00%
Two Independent Pricing Quotes [Member] | Privately Issued [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Recurring fair value measurements	$ 16	$ 16

Fair Value Measurements - Carry

Fair Value Measurements - Carrying Amounts and Estimated Fair Value for Financial Instrument Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Financial assets:
Interest-bearing deposits at banks	$ 20,888,341		$ 7,190,154
Investment securities	8,454,344		9,497,251
Federal funds sold			3,500
Loans and leases:
Allowance for credit losses	(1,638,236)	$ (1,384,366)	(1,051,071)	$ (1,029,867)	$ (1,019,337)	$ (1,019,444)
Loans and leases, net	96,119,312		89,871,798
Financial liabilities:
Noninterest-bearing deposits	(45,397,843)		(32,396,407)
Savings and interest-checking deposits	(63,623,406)		(54,932,162)
Time deposits	(5,078,426)		(5,757,456)
Deposits at Cayman Islands office	(868,284)		(1,684,044)
Long-term borrowings	(6,321,291)		(6,986,186)
Carrying Amount [Member]
Financial assets:
Cash and cash equivalents	1,354,815		1,432,805
Interest-bearing deposits at banks	20,888,341		7,190,154
Trading account assets	1,293,534		470,129
Investment securities	8,454,344		9,497,251
Federal funds sold			3,500
Loans and leases:
Consumer loans	15,782,773		15,386,693
Allowance for credit losses	(1,638,236)		(1,051,071)
Loans and leases, net	96,119,312		89,871,798
Accrued interest receivable	380,859		333,142
Financial liabilities:
Noninterest-bearing deposits	(45,397,843)		(32,396,407)
Savings and interest-checking deposits	(63,623,406)		(54,932,162)
Time deposits	(5,078,426)		(5,757,456)
Deposits at Cayman Islands office	(868,284)		(1,684,044)
Short-term borrowings	(52,298)		(62,363)
Long-term borrowings	(6,321,291)		(6,986,186)
Accrued interest payable	(104,301)		(105,374)
Trading account liabilities	(137,994)		(79,903)
Other financial instruments:
Commitments to originate real estate loans for sale	40,106		10,740
Commitments to sell real estate loans	(10,563)		300
Other credit-related commitments	(136,840)		(136,470)
Interest rate swap agreements used for interest rate risk management	(249)		(1,762)
Carrying Amount [Member] | Commercial Loans And Leases [Member]
Loans and leases:
Commercial loans and leases	29,203,862		23,838,168
Carrying Amount [Member] | Commercial [Member]
Loans and leases:
Commercial loans and leases	37,159,451		35,541,914
Carrying Amount [Member] | Residential Real Estate Loans [Member]
Loans and leases:
Commercial loans and leases	15,611,462		16,156,094
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member]
Financial assets:
Cash and cash equivalents	1,354,815		1,432,805
Interest-bearing deposits at banks	20,888,341		7,190,154
Trading account assets	1,293,534		470,129
Investment securities	8,561,449		9,539,540
Federal funds sold			3,500
Loans and leases:
Consumer loans	15,207,433		15,413,262
Loans and leases, net	95,538,814		90,668,624
Accrued interest receivable	380,859		333,142
Financial liabilities:
Noninterest-bearing deposits	(45,397,843)		(32,396,407)
Savings and interest-checking deposits	(63,623,406)		(54,932,162)
Time deposits	(5,118,204)		(5,829,347)
Deposits at Cayman Islands office	(868,284)		(1,684,044)
Short-term borrowings	(52,298)		(62,363)
Long-term borrowings	(6,366,011)		(7,063,165)
Accrued interest payable	(104,301)		(105,374)
Trading account liabilities	(137,994)		(79,903)
Other financial instruments:
Commitments to originate real estate loans for sale	40,106		10,740
Commitments to sell real estate loans	(10,563)		300
Other credit-related commitments	(136,840)		(136,470)
Interest rate swap agreements used for interest rate risk management	(249)		(1,762)
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets:
Cash and cash equivalents	1,307,683		1,394,984
Trading account assets	48,741		49,040
Investment securities	67,888		100,637
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Significant Observable Inputs (Level 2) [Member]
Financial assets:
Cash and cash equivalents	47,132		37,821
Interest-bearing deposits at banks	20,888,341		7,190,154
Trading account assets	1,244,793		421,089
Investment securities	8,417,724		9,351,793
Federal funds sold			3,500
Loans and leases:
Loans and leases, net	4,265,613		4,019,186
Accrued interest receivable	380,859		333,142
Financial liabilities:
Noninterest-bearing deposits	(45,397,843)		(32,396,407)
Savings and interest-checking deposits	(63,623,406)		(54,932,162)
Time deposits	(5,118,204)		(5,829,347)
Deposits at Cayman Islands office	(868,284)		(1,684,044)
Short-term borrowings	(52,298)		(62,363)
Long-term borrowings	(6,366,011)		(7,063,165)
Accrued interest payable	(104,301)		(105,374)
Trading account liabilities	(137,994)		(79,903)
Other financial instruments:
Commitments to sell real estate loans	(10,563)		300
Interest rate swap agreements used for interest rate risk management	(249)		(1,762)
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets:
Investment securities	75,837		87,110
Loans and leases:
Consumer loans	15,207,433		15,413,262
Loans and leases, net	91,273,201		86,649,438
Other financial instruments:
Commitments to originate real estate loans for sale	40,106		10,740
Other credit-related commitments	(136,840)		(136,470)
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Commercial Loans And Leases [Member]
Loans and leases:
Commercial loans and leases	28,736,876		23,510,908
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Commercial Loans And Leases [Member] | Significant Unobservable Inputs (Level 3) [Member]
Loans and leases:
Commercial loans and leases	28,736,876		23,510,908
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Commercial [Member]
Loans and leases:
Commercial loans and leases	35,781,888		35,517,180
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Commercial [Member] | Significant Observable Inputs (Level 2) [Member]
Loans and leases:
Commercial loans and leases	255,442		28,338
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Commercial [Member] | Significant Unobservable Inputs (Level 3) [Member]
Loans and leases:
Commercial loans and leases	35,526,446		35,488,842
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Residential Real Estate Loans [Member]
Loans and leases:
Commercial loans and leases	15,812,617		16,227,274
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Residential Real Estate Loans [Member] | Significant Observable Inputs (Level 2) [Member]
Loans and leases:
Commercial loans and leases	4,010,171		3,990,848
Cumulative Amount of Fair Value Hedging Adjustment Increasing (Decreasing) the Carrying Amount [Member] | Residential Real Estate Loans [Member] | Significant Unobservable Inputs (Level 3) [Member]
Loans and leases:
Commercial loans and leases	$ 11,802,446		$ 12,236,426

Commitments and Contingencies -

Commitments and Contingencies - Commitments and Contingent Liabilities Outstanding (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Commitments to extend credit
Home equity lines of credit	$ 5,556,034	$ 5,442,160
Commercial real estate loans to be sold	236,832	164,076
Other commercial real estate	8,640,169	9,029,608
Residential real estate loans to be sold	1,030,144	423,056
Other residential real estate	713,200	448,375
Commercial and other	18,256,994	16,170,731
Standby letters of credit	2,394,261	2,441,432
Commercial letters of credit	37,859	41,059
Financial guarantees and indemnification contracts	4,306,209	4,108,572
Commitments to sell real estate loans	$ 1,478,551	$ 906,037

Commitments and Contingencies_2

Commitments and Contingencies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2020USD ($)ESOP	Jun. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Loss Contingencies [Line Items]
Commitments to extend credit to commercial customers		$ 10,000,000,000	$ 9,100,000,000
Maximum credit risk for recourse associated with loans sold under Federal National Mortgage Association Delegated Underwriting and Servicing program		3,900,000,000	$ 3,900,000,000
Settlement amount	$ 88,000,000
Minimum [Member]
Loss Contingencies [Line Items]
Range of reasonably possible losses		0
Maximum [Member]
Loss Contingencies [Line Items]
Range of reasonably possible losses		$ 25,000,000
Employee Stock Ownership Plans [Member]
Loss Contingencies [Line Items]
Settlement amount	$ 80,000,000
Number of ESOPs | ESOP	21

Segment Information - Informati

Segment Information - Information about Company's Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Net income	$ 241,054	$ 473,260	$ 509,876	$ 956,002
Net Income (Loss)	241,054	473,260	509,876	956,002
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	1,444,410	1,553,576	2,950,575	3,104,401
Business Banking [Member]
Segment Reporting Information [Line Items]
Net income	37,563	42,250	70,489	85,521
Net Income (Loss)	37,563	42,250	70,489	85,521
Business Banking [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	138,086	140,767	275,919	280,089
Business Banking [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	144	1,004	1,029	1,860
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net income	111,030	123,507	254,762	255,725
Net Income (Loss)	111,030	123,507	254,762	255,725
Commercial Banking [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	287,525	278,110	579,301	545,600
Commercial Banking [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	249	887	1,302	1,727
Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Net income	107,083	121,629	224,491	239,127
Net Income (Loss)	107,083	121,629	224,491	239,127
Commercial Real Estate [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	227,113	225,442	450,418	444,615
Commercial Real Estate [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	60	406	469	760
Discretionary Portfolio [Member]
Segment Reporting Information [Line Items]
Net income	95,691	38,040	121,359	77,212
Net Income (Loss)	95,691	38,040	121,359	77,212
Discretionary Portfolio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	138,827	60,976	188,046	124,893
Discretionary Portfolio [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	(9,861)	(9,291)	(22,898)	(18,590)
Residential Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net income	37,400	7,642	62,016	20,583
Net Income (Loss)	37,400	7,642	62,016	20,583
Residential Mortgage Banking [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	142,045	96,449	267,606	180,210
Residential Mortgage Banking [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	21,016	17,150	42,433	31,664
Retail Banking [Member]
Segment Reporting Information [Line Items]
Net income	86,498	140,494	196,744	285,560
Net Income (Loss)	86,498	140,494	196,744	285,560
Retail Banking [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	353,521	436,593	756,204	867,484
Retail Banking [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	267	2,787	534	5,298
All Other [Member]
Segment Reporting Information [Line Items]
Net income	(234,211)	(302)	(419,985)	(7,726)
Net Income (Loss)	(234,211)	(302)	(419,985)	(7,726)
All Other [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Revenues	157,293	315,239	433,081	661,510
All Other [Member] | Intersegment Activity Eliminated in Consolidated Totals [Member]
Segment Reporting Information [Line Items]
Total Revenues	$ (11,875)	$ (12,943)	$ (22,869)	$ (22,719)

Segment Information - Summary o

Segment Information - Summary of Segment Information (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Segment Reporting Information [Line Items]
Average Total Assets	$ 128,513	$ 119,584	$ 117,667
Business Banking [Member]
Segment Reporting Information [Line Items]
Average Total Assets	7,235	5,793	5,724
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Average Total Assets	30,603	28,142	27,981
Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Average Total Assets	25,340	23,921	23,720
Discretionary Portfolio [Member]
Segment Reporting Information [Line Items]
Average Total Assets	26,821	29,081	29,888
Residential Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Average Total Assets	3,113	2,611	2,173
Retail Banking [Member]
Segment Reporting Information [Line Items]
Average Total Assets	16,039	15,083	14,580
All Other [Member]
Segment Reporting Information [Line Items]
Average Total Assets	$ 19,362	$ 14,953	$ 13,601

Segment Information - Summary_2

Segment Information - Summary of Segment Information (Parenthetical) (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting [Abstract]
Taxable-equivalent adjustment	$ 4,234,000	$ 5,925,000	$ 9,297,000	$ 11,892,000

Relationship with Bayview Len_2

Relationship with Bayview Lending Group LLC and Bayview Financial Holdings, L.P. - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Loan facility carrying amount	$ 6,321,291,000		$ 6,321,291,000		$ 6,986,186,000
Bayview Lending Group [Member]
Schedule of Equity Method Investments [Line Items]
Carrying value of minority interest investment in Bayview Lending Group LLC	0		0
Income (loss) from equity method investments	0	$ 0
Bayview Lending Group [Member] | Other Revenues From Operations [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	23,000,000	37,000,000
Bayview Lending Group and Bayview Financial [Member]
Schedule of Equity Method Investments [Line Items]
Outstanding principal balances of mortgage servicing rights	2,100,000,000		2,100,000,000		2,200,000,000
Revenue from contract with customer	2,000,000	3,000,000	5,000,000	$ 6,000,000
Bayview Financial [Member]
Schedule of Equity Method Investments [Line Items]
Outstanding principal balances of residential mortgage loans from Bayview Financial	64,700,000,000		64,700,000,000		62,800,000,000
Revenues from sub-servicing	34,000,000	$ 29,000,000	71,000,000	$ 57,000,000
Investment securities in held-to-maturity portfolio securitized by Bayview Financial	86,000,000		86,000,000		$ 93,000,000
Secured loan facilities carrying amount	100,000,000		100,000,000
Outstanding balance of secured debt	199,000,000		199,000,000
Bayview Financial [Member] | Syndicated Loan Facility [Member]
Schedule of Equity Method Investments [Line Items]
Loan facility carrying amount	1,000,000		1,000,000
Bayview Financial [Member] | Syndicated Loan Facility [Member] | M&T Bank [Member]
Schedule of Equity Method Investments [Line Items]
Loan facility carrying amount	$ 168,000,000		$ 168,000,000

Recent Accounting Developments

Recent Accounting Developments - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Allowance for credit losses	$ 1,638,236	$ 1,384,366		$ 1,051,071	$ 1,029,867	$ 1,019,337	$ 1,019,444
Cumulative effect adjustment to retained earnings	$ 12,919,345			$ 12,820,916
ASU 2016-13 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Allowance for credit losses			$ 132,000
ASU 2016-13 [Member] | Cumulative Effect Period of Adoption Adjustment [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Cumulative effect adjustment to retained earnings			$ 132,000